Si Antonio estuviera en la fiesta, el hablaria con Juan.
This sentence means - If Antonio had gone to the party, he would have talked to Juan.
It is a hypothetical sentence, meaning that it didn't happen but states what could have happened had he decided to go to the party.
Answer:
I can't answer it because is on Portuguese, I dont know Portuguese, sorry
It should be A. Because on C. it's not written properly and you're not really changing anything for B.
