Ayuda por favor es una tabla de la tierra

Completa la oración con la voz pasiva con se. used cars for sale. carros usados. (there are no option choices, write the answer in the passive tense, don't use google translate)

When could you attach the direct object pronoun to an infinitive verb? a: when an infinitive verb follows a conjugated verb. b: when an infinitive verb ends in a question. c: when a stem-changing verb ends in a question. d: when a stem-changing verb follows a conjugated verb.

If the pants costs $233 how would you respond to the question ¿cuánto cuestan los pantalones?