Eduardo: <em>¿Compraste el libro para Mateo? </em>
Fernando: <em>Sí</em>, _______ <em>compré</em>.
Translation:
Eduardo: Did you buy the book for Mateo?
Fernando: Yes, [blank] I bought.
<u>The options</u>
A. <em>los</em> - the ~masc. plural (definite article)
B. <em>les</em> - them, you ~masc. plural (indirect object pronoun)
C.<em> las</em> - the, them ~fem. plural (definite article, indirect object pronoun)
D.<em> lo </em>- the, it, him ~masc, singular (definite article, direct object pronoun)
First of all, our direct object (<em>el libro</em>) is masculine singular. That eliminates all options but one. Another thing that points to (D) as the correct answer is that none of the other options are direct object pronouns.
<h3>
Answer:</h3>
D.<em> lo</em>