Question

select the one common noun.
during his vacation in california, jayden visited the san diego zoo.

Explanation:

A common noun is a general name for a person, place, thing, or idea, not specific. In the sentence "During his vacation in California, Jayden visited the San Diego Zoo", "zoo" is a common noun as it's a general term for a place where animals are kept, while "California", "Jayden", and "San Diego Zoo" are proper nouns (specific names).

Answer:

zoo