Answer:
B. 
Explanation:
Assuming we are dealing with a perfect gas, we should use the perfect gas equation:

With T the temperature, V the volume, P the pressure, R the perfect gas constant and n the number of mol, we are going to use the subscripts i for the initial state when the gas has 20 cubic inches of volume and absolute pressure of 5 psi, and final state when the gas reaches 10 psi, so we have two equations:
(1)
(2)
Assuming the temperature and the number of moles remain constant (number of moles remain constant if we don't have a leak of gas) we should equate equations (1) and (2) because
,
and R is an universal constant:
, solving for 


Answer
Explanation:
The question was incomplete as the events are not given in the question. However the answer to your question is given as follows. The correct order of the events from youngest (top) to oldest (bottom) is given as follows.
Moon formation
↑
Earth formation
↑
Nuclear fusion in protosun
↑
BigBang