Question

Which sentence uses a verb that agrees with its subject? A. The snails in the garden moves slowly. B. The stripes on the American flag are white and red. C. Authors of books receives royalties for their work. D. A bag of groceries were found outside the store.

Answer 1

in A the verb should be "move"

in B - correct! the verb should be as it is!

in C the verb should be "receive"

in D the verb should be "was"

in the options were the verb is not correct the problem is the agreement in number: singular/plural.