单选题 Due to popular demand by the staff members, the scheduled talk by Mr. Smith will take place ______ Room 15 instead of Room 20 as was first planned.
A. in B. on C. of D. as

【正确答案】 A

【答案解析】[解析] 由于员工的普遍要求，史密斯先生原定在15号房间进行的演讲将在20号房间进行。本题需选择适当的介词in，故选A。