In which sentence does the verb agree with the subject?

a.
the martian chronicles explores the idea of life on mars.

b.
across five aprils are about soldiers in the civil war.

c.
the hundred dresses were illustrated by louis slobodkin.

The sentence in which the verb agrees with the subject is: The Martian Chronicles explores the idea of life on Mars. The answer is option A. The subject of the sentence is "The Martian Chronicles". This takes the singular form of the verb which is "explores" because it is a title of a book. All titles, regardless of the plural form, will always take the singular form.