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.

A:) When an infinitive verb follows a conjugated verb.

Explanation: in indicative sentences that use infinitives, you can either attach the direct object pronoun to the end of the infinitive verb or put it before the first conjugated verb.

Voy a comprar un coche.

I'm going to buy a car.

Direct object is car.

Direct object pronoun is "lo", masculine and singular.

Voy a comprarlo.

I'm going to buy it.

Lo voy a comprar.