He asked the hotel receptionist, “Can you tell me the tariff for the rooms?” Which option best transforms this into an indirect question?

A. He asked the receptionist that if he can tell him the tariff of rooms.
B. He asked the receptionist to tell him the tariff of rooms.
C. He enquired the receptionist if he can tell him the tariff of rooms.
D. He asked the receptionist if he could tell him the tariff of rooms.
Answer: D. He asked the receptionist if he could tell him the tariff of rooms.