What do you mean by rate of climb?

A)
Drag polar
B)
Thrust required
C)
Lift of an aircraft
D)
Vertical velocity of an aircraft

Correct Answer :   Vertical velocity of an aircraft


Explanation : Rate of climb is nothing but the vertical velocity of aircraft. It is the climbing rate of an aircraft. Lift is an aerodynamic force which holds the aircraft in the air. Weight is the force acting due to gravity. Thrust is propulsive force.