In this situation, you should ask the caller to hold on for a moment, and thank them when they're agree.
But, since you're handling the person on the phone first, you need to smile to the person in front of you, and politely ask him/her to wait until you finish your call. After you handle the person on the phone than you could proceed as usual with the person in front of you.
The answer is letter A.
The design of the houses of the people in Mesopotamia is made up of MUD. The houses of these people are similar but not exactly the same the houses today. Though the door are sometimes made of wood but the major material that is used is mud
