Given,

The angle of incident =i

Prism small angle =A

Refractive material of the prism =μ

Let the angle of emergence =e

Now, it is given that the incident ray emerges normally from the opposite surface of the prism so the angle of emergence becomes zero.

⇒∠e = 0 .........(i)

Let angle of deviation in the prime be δ

So, as we know the relation between the angle of deviation (δ), small angle of prism (A) and the refractive index of the prism μ which is given as,

⇒ δ =(μ−1)A .........(ii)

Now, as we know in a prism, a small angle of prism plus an angle of deviation in a prism is equal to the sum of angle of incidence and angle of emergence.

Therefore, we have,

⇒ δ + A= i + e .......(iii)

Now, substitute the value from equation (i) and (ii) in equation (iii) we have,

⇒(μ−1) A+A = i+0

Now, simplify the above equation we have,

⇒μA − A + A = i

Now, cancel out the positive, negative same terms we have,

⇒ i = μA

So, this is the required angle of incidence such that the prism has a small angle A and emerges normally from the opposite surface.

Hence, the correct option is (C).

Endomembrane system consist of endoplasmic reticulum, Golgi complex, vacuoles and lysosomes. 

Mitochondria is semi-autonomous cell organelle. 

Ribosome is non-membranous cell organelle.

Hence, the correct option is (C).

Protista is a kingdom in which single-celled eukaryotic organisms are present. Protists don't have well-defined cell boundaries due to the presence of the nucleus. They form a link in different categories. The cell body of Protista contains a well-defined nucleus and membrane-bound organelles. Along with that some have cilia and some have flagella are also present that help in movement. Protist reproduces asexually as well as sexually depending on the external environment. So they show similarity with Plantae, fungi, and Animalia because they all are also eukaryotes.

Hence, the correct option is (D).

In the third week, the primordial germ cells wander - in an amoeboid manner - from the primary ectoderm into the yolk sac wall and collect near the exit of the allantois. The primordial germ cells are now extraembryonal, lying in the endoderm and mesoderm of the yolk sac wall.

Hence, the correct option is (A).

The aerodynamic diameter of an irregular particle is signified as the diameter of the spherical particle with a density of 1000 kg/m3 and the same settling velocity as the irregular particle. It indicates the equivalent diameter of a sphere having the same volume as that of the Aerosol.

One can apply the aerodynamic diameter to particulate pollutants or to inhaled drugs to predict where in the respiratory tract such particles deposit. Pharmaceutical companies typically use aerodynamic diameter, not geometric diameter, to characterize particles in inhalable drugs.

Aerosols are defined as a combination of the liquid or solid particles suspended in a gaseous or liquid environment.

In the atmosphere, these particles are mainly located in the low layers of the atmosphere (< 1.5 km) since aerosol sources are located on the terrestrial surface.

Hence, the correct option is (D).

The temperature at which vapor pressure of liquid becomes equal to the atmospheric pressure is called the boiling point of the liquid.

Boiling points of hydrocarbons like alkanes are affected by several factors.

For alkanes, the boiling point increases as molecular mass increases. This is because the intermolecular Van der Waals force increases as molecular size increases.

Hexane, 2 -methylpentane, 3 -methylpentane, and 2,2 -dimethylbutane have the same molecular formula but different structural formula. Such compounds are called structural isomers of each other. These structures differ in the length of continuous parent carbon chains. The structures are as follows-

For isomeric alkanes, we observe an interesting pattern in the boiling point. In case of isomeric alkanes, the boiling point decreases as branching in the molecule increases. This is because as the number of branched chains in the molecule increases it gains the shape like a sphere. Now because of the spherical shape, the molecule has less area of contact and therefore the intermolecular force between the spherical molecules becomes weak. Now, these weak intermolecular forces can be overcome at relatively low temperatures.

In the above structures, we can see that 2,2 -dimethylbutane has the highest branching as compared to the other structures. Hence it will have the lowest boiling point.

Hence, the correct option is (D).