What can you do if you are not familiar with an allusion referenced in a text- O Look for analogies.
O Define the allusion
o Use context clues.
O Look up the word or phrase.

Look up the word or phrase.

Explanation:

An allusion is a figure of speech used to refer to something, like a person, a place, or even an event, without naming it explicitly.

However, since allusions refer to something different from the subject at hand, the reader could not recognize the reference point.

For example, in Fahrenheit 451 there´s an allusion to the volcano Vesuvius ("Mildred ran from the parlor like a native fleeing an eruption of Vesuvius"). Those who don´t know the story about the Vesuvius´eruption should look up that word to understand the meaning of that sentence.

the answer should be d) he was one of those young thousands who greeted the war with a certain amount of relief, welcoming the liberation from webs of tangled emotion" since it is the best option because it shows his desire to free himself.

hope this answer you! have a great day.