One evening Mr.Harris was on duty when the phone rang．He went to answer it．It was Mrs.Green“Please,sir,come to my house．

One evening Mr.Harris was on duty when the phone rang．He went to answer it．It was Mrs.Green“Please,sir,come to my house．I had 5,000 dollars stolen．”     Mr.Harris hurried to her house．He asked Mrs.Green,When did you find the money missing?  “At seven,I put my money on the table in the living - room.Then I went to wash my hair.I came back at seven thirty and the money was gone.” “I see.” Mr.Harris said.“Were you alone in the house?” “No.My sister's daughter,Nancy,was here,too.” “Let's talk to Nancy,” said Mr.Harris.They went to Nancy's room.    Mr.Harris sat on the only chair in the room.The chair was cold.Mrs.Green and Nancy sat on the bed.Mr.Harris saw some books on the floor near the chair.“What have you been doing this evening?”     “I've been studying because I shall have a test tomorrow.I've been sitting on that chair reading all the time.I never got up and never left my room.But at seven fifty I heard a sound,like someone closing the door.I didn't go out to have a look,for I was too busy.Maybe someone came into the house and took my aunt's money,”      After hearing that,Mr.Harris was quite clear.He said to Mrs.Green,“Well,you won't have to be worried and you'll find the 5,000 dollars just in the room.” 4.Marris paid attention to all the facts except the fact that----- A.Nancy and her ant sat on the bed.B.some books were on the floor C.there was only one chair in the room.D.the chair was cold.请问一下选什么?