Mark the letter A, B, C, or D to indicate the sentence that best combines each pair of sentences given.Câu hỏi It's a long trip to the world heritage site. We have to start off early and come back in the afternoon. A. It's a long trip to the world heritage site, but we have to start off early and come back in the afternoon. B. It's a long trip to the world heritage site because we have to start off early and come back in the afternoon. C. It's a long trip to the world heritage site, so we have to start off early and come back in the afternoon. D. It's a long trip to the world heritage site if we have to start off early and come back in the afternoon.