A Model Rocket Sits on the Launch Pad Until Its

Multiple Choice

A model rocket sits on the launch pad until its fuel is ignited,blasting the rocket upward.During the short time of blast-off,as the ignited fuel goes down,the rocket goes up because:

A) the fuel pushes on the ground.
B) air friction pushes on the escaping fuel.
C) the downward force of gravity is less than the downward momentum of the fuel.
D) of none of the above reasons.