Answer
As a system undergoes a constant volume process,
(c) the work done on or by the system is zero.
Work Step by Step
The work done by a gas is $P \Delta V$
The work done on a gas is $-P \Delta V$
If $\Delta V = 0$, then the work done on or by the system is zero.
As a system undergoes a constant volume process,
(c) the work done on or by the system is zero.