Which sentence shows the correct placement of the words "se lo"

a- el muchacho dio se lo
b-se lo el muchacho dio
c-el muchacho se lo dio

Correct C. el muchacho se lo dio

This is the case of indirect and direct object working together. An Indirect Object Pronoun is a person that, in an indirect way, takes the action of a verb. So it tells us to whom or for whom an action is done. On the other hand, a direct object is a noun that receives, in an direct way, the action of a verb and the direct object pronoun replaces the direct object. So lo is the direct object pronoun for the third person singular in masculine form while se comes from the indirect object le or les because these two form changes to se when working along with a direct object pronoun.

Why’d you put this in the spanish subject? ?

Pedro, josie, y heather fue a la quinceañera de virginia. the question is asking who went to the quinceañera. the person answering the question should answer using the ellos, ellas, and ustedes form if they were not part of that group of people.