The Ridgeview High drama club's presentation of The Phantom of the Opera was their most lavish production to date. In this sentence, most lavish is a/an

C. Superlative.

Explanation:

Adjectives describe the nouns or pronouns in the sentence. They add extra details to the noun or pronoun that is being described.

In the given sentence, "most lavish" is the superlative form of adjectives of comparison. The comparative form is "more lavish" and this is due to the fact that adjectives with two or more syllables use "more" and "most" to their comparative and superlative degrees of comparison.

Thus, the correct answer is C.