The simile in the excerpt is "His beard was as white as snow." A simile is a comparison between two things using like or as. In this simile the color of his beard is compared to the snow. As to the other options, personification is giving a nonhuman thing human-like traits. Everything in the excerpt is human. Allusion is a reference to another literary work. There is no reference. Metaphor is a comparison between two things without using like or as. This uses as so it is a simile and not a metaphor.
Question 5: He plans to pretend that he has gone mad.
When Hamlet talks about "an antic disposition", he means that he is going to change his mood to one of madness. It is important to remember that mad actually means insane or crazy, not angry.
Question 6: Hamlet is saying that his madness changes like the weather, and that he is only mad some of the time.
In this piece of dialogue Hamlet is speaking of his madness like it's the wind. The wind changes directions just like his madness can change. He is trying to tell his friends that his madness is not constant but instead changes.
From the excerpt of "Dover Beach" by Matthew Arnold, the line "...on the French coast, the light/Gleams and is gone..." obviously symbolizes the impermanence of life. The light on the French coast is like an opportunity presented to us, once. We must be ready once this opportunity comes.