Answer: C. gravitational kinetic
Explanation: Gravitational potential energy is the energy calculated from an object's mass height and the acceleration due to gravity. The gravitational potential energy is the energy an object has as a result of the position of the object in a gravitational field.
Can I see the book you read for I can answer and it more info because your question doesn’t make sense
Explanation :
The forces acting on hot- air balloon are:
Weight, (W)
Force due to air resistance, (F)
Upthrust force, (U)
Its weight W is acting in downward direction. The upthrust force U acts in upward direction. When the balloon is moving upward, the air resistance is in downward and vice versa.
In this case, the hot-air balloon descends vertically at constant speed.
so, 
and 
so,
....................(1)
when it is ascending let the weight that it is releasing is R, so
..........(2)
solving equation (1) and (2)

2F is the weight of material that must be released from the balloon so that it ascends vertically at the same constant speed.
Answer: It frees up valuable portions of the broadcast spectrum, it has better audio and picture quality, and there are more options on digital broadcasting
Explanation:
F=ma, in this case your force=-883 N and mass = 90 kg. F/m=a therefore acceleration=-883/90=-9.81 m/s/s