The internal energy of a system is always increased by . A. adding heat to the system B. adding heat to the system and having the system do work on the surroundings C. withdrawing heat from the system D. having the system do work on the surroundings

B. adding heat to the system and having the system do work on the surroundings

Explanation:

The internal energy of a system is the energy contained within the system. From first law of thermodynamics we have the equation : dq=du+dw

and we know that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another therefore du is zero. dq = dw this means that the entire heat supplied is converted into work (on the surroundings)

However, some of the heat supplied is also used to increase the internal energy of the system

the answer your looking for is c).

it's 3.2 on edge, i just took the test.