Campaign = an organized course of action to achieve a goal.

Cruise = sail about in an area without a precise destination, especially for pleasure.

Patrol = an expedition to keep watch over an area, especially by guards or police walking or driving around at regular intervals.

Explore = travel through (an unfamiliar area) in order to learn about it.

Hence, option C is the correct answer.

Souvenir = a thing that is kept as a reminder of a person, place, or event.

Relic = a part of a deceased holy person's body or belongings kept as an object of reverence.

Trophy = a cup or other decorative object awarded as a prize for a victory or success.

Memento = an object kept as a reminder of a person or event.

Hence, option B is the correct answer.

Charity = an organization set up to provide help and raise money for those in need.

Honorary = conferred as an honour, without the usual requirements or functions.

Startup = the action or process of setting something in motion.

Freelance = self-employed and hired to work for different companies on particular assignments.

Hence, option B is the correct answer.

Astronaut = a person who is trained for travelling into space.

Physicist = a person who studies or is an expert in physics.

Pilot = a person who flies an aircraft.

Scientist = a person who studies or teaches science.

Hence, option A is the correct answer.

Eulogy = A formal expression of praise for someone who has died recently

Prologue = An introduction to a play

Epilogue = A short speech (often in verse) addressed directly to the audience by an actor at the end of a play

Chorus = Any utterance produced simultaneously by a group

Hence, option C is the correct answer.

Lyric = (of poetry) expressing the writer's emotions, usually briefly and in stanzas or recognized forms.

Ode = a lyric poem, typically one in the form of an address to a particular subject, written in varied or irregular metre.

Elegy = (in modern literature) a poem of serious reflection, typically a lament for the dead.

Sonnet = a poem of fourteen lines using any of a number of formal rhyme schemes, in English typically having ten syllables per line.

Hence, option C is the correct answer.

Legible = capable of being read or deciphered.

Corrigible = capable of being corrected, rectified, or reformed.

Negligible = so small or unimportant or of so little consequence as to warrant little or no attention.

Illegible = not clear enough to be read.

Hence, option D is the correct answer.

Irrefutable: Impossible to deny or disprove

Inaccurate: Not accurate

Infallible: Incapable of failure or error

Inevitable: Invariably occurring or appearing

Hence, option C is the correct answer.

Historian = an expert in or student of history, especially that of a particular period, geographical region, or social phenomenon.

Sociologist = an expert in or student of the development, structure, and functioning of human society.

Archaeologist = a person who studies human history and prehistory through the excavation of sites and the analysis of artefacts and other physical remains.

Antiquarian = relating to or dealing in antiques or rare books.

Hence, option D is the correct answer.

Sanctuary = a refuge for wildlife where predators are controlled and hunting is illegal.

Oasis = a fertile tract in a desert (where the water table approaches the surface).

Asylum = a shelter from danger or hardship.

Retreat = withdrawal of troops to a more favorable position to escape the enemy's superior forces or after a defeat.

Hence, option A is the correct answer.