The correct answer to your question is option D. The key to finding the answer to these kinds of question is to look at the adjective of the sentence. In the sentence given you can see the adjective given was entrar,, or enter. Now in order to find out whether or not the boy (niño) entered the house (casa),, we must look for entrar in the sentences given. As you can see,, the only option that has the adjective entrar in it is option D,, making it your correct answer.
Let me know if you have any further questions
:)
