The dog always snuggles next to me on the couch. The cats always snuggle next to me on the couch.
The answer to this is B. Snuggle.
The cats is plural, the dog is not plural. In the sentence, we would have to take the not plural 'the dog' first as it comes after the plural 'the cats' in one running sentence. So "snuggle" could be used for both the cats or the dog, but not snuggles.
