Answer:
C) tests the functioning of the system as a whole.
Step-by-step explanation:
System testing refers to a process in which a complete system is evaluated to make sure that it works properly and fulfills the requirements. According to this, the answer is that system testing tests the functioning of the system as a whole.
The other options are not right because system testing doesn't separate components or programs as it involves the actual evaluation of the whole system to find defects and it is done before the acceptance testing.