The tiny bunnies in the nest will have floppy ears.
Answer:
bunnies
Step-by-step explanation:
In this sentence, the adjectival prepositional phrase in the nest modifies the noun bunnies.
Adjectival prepositional phrases modify nouns or pronouns. There are no pronouns in the sentence. The other noun ears is the object of the verb and cannot be modified by the adjectival phrase in the nest. So the correct answer would be bunnies.