The process in which a substance changes from a gaseous state to the liquid state is
a. critical temperature.
b. absolute zero.
c. evaporation.
d. condensation.

By definition we have to:

In physics, condensation is a change of state by which a substance passes from a gaseous state to a liquid state.

For example, in a refrigeration cycle, the refrigerant leaves the compressor in the gaseous state, from here, it enters the condenser, a state change called condensation occurs and the refrigerant leaves in liquid form. This process is useful in air conditioners.

The process in which a substance changes from a gaseous state to the liquid state is:

D. condensation.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

read more on -

thermal energy is the answer