How much heat had to be put in during the process to increase the internal energy of the gas by 1.80×10^4 J?
a) Q = 1.80 * 10^4 J
b) Q = -1.80 * 10^4 J
c) Q = 0.50 * 10^4 J
d) Q = -0.50 * 10^4 J