And then it started like a guilty thing
Upon a fearful summons
what is the simile comparing “it” to?
A. a fearful summons. B. the feeling of dead. C. a guilty person. D. a court summons

B.

"it" refers to a pronoun, specific for animals or subjects, so C. wouldn't be an option.

And "summon" in meaning of "request someone to present" in this sentence, could be put like this:

when the fearful summons going into someone's ear (we don't know who), it trigger the person to have guilty feeling and also the fear of possibly dying.

every person should make it a priority to serve at least two hours per week.

it's an extremely important civic responsibility that is invaluable to citizens most in need is the correct one

the answer is definitely option c. "sonnet xxxi best illustrates the division. in the octave, the poet observes that the moon is in love. in the sestet, he gives his reaction to the fickleness of woman's love."