Question 18: We had the printer ________ but they couldn’t work out wh

Question 18: We had the printer ________ but they couldn’t work out what the problem was; they said it was just too old a model.

• A. to be serviced
• B. having serviced
• C. serviced
• D. to service

have sb do st: nhờ ai đó làm gì => bị động: have st done by sb: có cái gì được làm bởi ai