Final answer:
The appropriate form of the verb salir to fill in the blank is salieron.
Step-by-step explanation:
The appropriate form of the verb salir to fill in the blank in the given sentence is salieron.
Esos chicos salieron del restaurante antes de nosotras.
This sentence is written in the past tense, and the subject 'esos chicos' (those boys) requires the third person plural form of the verb.
Therefore, the correct answer is D. salieron.
Learn more about Spanish Verbs