Which words make up the adverb phrase in the sentence? Which word does the adverb phrase modify?

Throughout the thunderstorm, my little puppy whined softly.

A.

Throughout the thunderstorm; modifies whined

B.

my little; modifies puppy

C.

whined softly; modifies puppy

D.

my little puppy; modifies whined

So we have three modifiers here, little, softly, and throughout the thunderstorm.

Little is describing the puppy, which is a noun. Therefore little is an adjective, not an adverb.

Softly is describing the whining, which is a verb. Therefore, softly is an adverb. However! It is not one of the answers, and I guess it isn't really a whole phrase.

Throughout the thunderstorm describes the whining, which is a verb.

Therefore, throughout the thunderstorm is an adverb, and fits our answer A.