We make a graphic of this problem to define the angle.
The angle we can calculate through triangle relation, that is,
With this function we should only calculate the derivate in function of c
That is the rate of change of 
.
b) At this point we need only make a substitution of 0 for c in the equation previously found.
Hence we have finally the rate of change when c=0.
1.6764 meters. You can also google inches to meters for your answer.
Ideal gas law:
PV = nRT
P = pressure, V = volume, n = # of moles, R = gas constant, T = temperature
Equipartition theorem:
Each degree of freedom that a molecule has adds 0.5kT to its total internal energy where k = Boltzmann's constant and T = temperature
2nd law of thermodynamics:
A set of governing principles that restrict the direction of net heat flow (always hot to cold, heat engines are never 100% efficient, entropy always tends to increase, etc)
Clearly the answer is Choice A
