Answer:
A. There is no direct object in the first sentence.
B. The direct object in the second sentence is "it" which refers to "this corn."
Step-by-step explanation:
In the first sentence, "La vaca responde" is the subject-verb-object construction where "vaca" is the subject, "responde" is the verb, and there is no direct object. The sentence simply states that the cow responds to a question or statement.
In the second sentence, "¿Puedes usarlo?" is the subject-verb construction where "puedes" is the verb and "usarlo" is the direct object. "Usarlo" is a pronoun that replaces "este maíz" from the previous sentence. Therefore, the direct object in the second sentence is "it," which refers to "this corn."