The students began whispering and giggling once they saw the teacher close the book.

The adverb clause once they saw the teacher close the book modifies

A) the verb began.

B) the noun teacher.

C) the noun students.

D) the verbs whispering and giggling.

Respuesta :

D) the verbs whispering and giggling.
I am pretty sure the correct answer is D) the verbs whispering and giggling.
Good Luck!! :)