In Physics, We Typically Write the First Law of Thermodynamics

In physics, we typically write the first law of thermodynamics as ΔU = Q W. The variable Q represents ___ and the variable W represents ___.

A) the internal energy of the system; the work done on a system by its surroundings
B) the internal energy of the system; the work done by a system on its surroundings
C) the heat flow into the system; the work done by a system on its surroundings
D) the temperature of the system; the work done by a system on its surroundings
E) the heat flow into the system; the internal energy of the system