C is the awnser because c is single replacement
Answer:

Explanation:
A body has acceleration when there is a change in the velocity vector, either in magnitude or direction. In this case we only have a change in magnitude. The average acceleration represents the speed variation that takes place in a given time interval.
a)

b)

Yes, an increase in temperature is accompanied by an increase in pressure. Temperature is the measurement of heat present and more heat means more energy. Molecules in hotter temperatures move faster and more often, eventually moving into the gaseous phase. The molecules would fill the container, and the hotter it got the more they would bounce off the walls, pushing outward, increasing the pressure.
I suppose you could measure this with some kind of loosely inflated balloon and subject it to different temperatures and then somehow measure the size/pressure of it.
The conservation of energy always holds true even when not clearly observable in machines that are less than 100% efficient. More often than not a machine will suffer energy losses (e.g. consider for a cooling fan: friction between the rotating blades, drag resistance in the air the fan is pushing around, resistance in the wire, and heat radiating/conducting away from the circuitry).