Mark the letter A, B, C, or D to indicate the sentence that best combines each pair of sentences in the following questions.
We came in the room. Our boss was sitting in the front desk.
A.We came in the room, our boss was sitting in the front desk.
B.When we came in the room, our boss had been sitting in the front desk.
C.When we came in the room, in the front desk was sitting our boss.
D.Hardly had we come in the room when our boss sat in the front desk