Answer:
C. Liz, who could always make people laugh, was loved by the whole block.
Step-by-step explanation:
Adjective clauses are those that modify, describe or give more information about nouns. We can identify them because they are usually placed right next to the noun they describe, and beginning with a relative pronoun (namely, who, whom, whose, that or which) or a relative adverb (when, where or why). In sentence C, the adjective clause is “who could always make people laugh” because it gives us more information about the noun “Liz.” Furthermore, it begins with the relative pronoun “who.”