Could you choose sentence belongs to the background part? (7.0分) A. Much to my regret, I am writing to place a complaint against one of your shop assistant. B. Yesterday at about ten o’clock in the morning, my husband and I, and a lady friend of ours from the US, came to your shop with the intention of buying some souvenirs. C. She rudely turned a deaf ear to the request and walked away murmuringsomething unpleasant. D. Looking forward to hearing from you.