Final answer:
The correct answer is C. deben.
Step-by-step explanation:
The subject of this question is Spanish. The correct answer is C. deben. This is the appropriate form of the verb deber (to have to/should) when referring to the plural pronoun 'ustedes' (you all). In this case, the statement is saying 'You all should go to Teotihuacán'.
Learn more about Spanish verbs