Suppose 150 Joules of Work Is Done on a System

Multiple Choice

Suppose 150 Joules of work is done on a system and that 300 Joules of heat are delivered to the system. Which of these is predicted by the first law of thermodynamics?

A) The internal energy U of the system increases by 450 J, since Q = +300 and W = -150.
B) The internal energy U of the system decreases by 150 J, since Q = -300 and W = +150.
C) The internal energy U of the system increases by 150 J, since Q = +300 and W = +150.
D) The internal energy U of the system does not change.