Mark the letter A, B, C, or D to indicate the sentence that best combines the sentences given

Mark the letter A, B, C, or D to indicate the sentence that best combines the sentences given.
37. My back was still painful. I went to see a doctor.
A. My back was still painful, but I went to see a doctor.
B. My back was still painful, so I went to see a doctor.
c. I went to see a doctor although my back was still painful.
D. My back being painful, so I went to see a doctor.
38. Mi didn't come to class yesterday. This surprised all of us.
A. Mi didn't come to class yesterday that surprised all of us.
B. This Mi didn't come to class yesterday surprised all of us.
c. Which surprised all of US that Mi didn't come to class yesterday.
D. Mi didn't come to class yesterday, which surprised all of us.

39. Teachers don't like it when you talk. They are trying to teach.
A. Teachers don't like it when you talk while they are trying to teach.
B. Teachers don't like it when you talk because they are trying to teach,
C. If teachers don't like it when you talk, they are trying to teach.
D. As teachers don't like it when you talk, they are trying to teach.
40. The street is so crowded. I can't go through it.
A. The street is so crowded and I don't want to go through it.
B. It is such a narrow street that I can't go through it.
c. It is such a crowded street that I can't go through it.
D. I can't go through the street on a crowded day.