Right answer:
a. Los chicos son talentosos
This sentence stands for the simple present tense. The word son is the conjugation of the verb ser that matches the third person plural in the simple present. On the other hand, talentosos is an adjective that means talented. Recall that an adjective is a word that gives us more information about a noun or pronoun. Therefore:
The boys are talented means Los chicos son talentosos
