My ( paternal ) grandmother treated us to dinner . Theresa came over Sunday and went to church and dinner with us . Then she came back to our house so I could help her with her research paper . We were up until midnight working on that thing .

Question: Why were we up so late working on what we were working on ?
Answer: The dinner needed to decorated before being eaten .I wanted to help her finish her research paper .The dinner needed to be cooked no matter how long it takes .None of the above choices .