To activate landing gear warning horn, which of the following in

To activate landing gear warning horn, which of the following information is required?

A.Landing gear lever position and thrust lever position.

B.Radio altimeter. thrust lever position and flaps position.

C.Radio altimeter. thrust lever position, flaps position and actual landing gear position.

D.Thrust lever position. flaps position and actual landing gear position.

正确答案是C