2377 Mock exam question, help please I'm stuck

[TraineeSparkee]

I'm doing a mock exam for my 2377. The question is: An insulation resistance tester should be capable of:

a) delivering a minimum voltage of 1000 V d.c
b) testing the continuity of an earthing circuit
c) delivering a maximum voltage of 25A through the load
d) maintaining the test voltage across the load

I think the correct answer is D but cant find the answer to this anywhere!!!

 

[telectrix]

it is (d) because it's none of the other 3.