Answer:
B) gravity
Step-by-step explanation:
For a rocket to launch, it must overcome the force of gravity acting on it. For this, it produces an upward force (thrust) that "fights" against the force that is pulling it downward (gravity).
To produce the buoyant force, the rocket engines produce combustion gases, usually using liquid hydrogen as fuel and liquid oxygen as the oxidizer, these gases are expelled by the rocket nozzles, pushing against the upper wall of the nozzles. The relationship between the forces can be summed up by Newton's third law, in which every action causes a reaction of equal force and direction and opposite direction, the gases are expelled with such a force that it exceeds the force of the rocket, propelling it upwards .