The correct answer is: C. Either I or II follows
The CBI should try to catch the officer red-handed and then take a strict action against him. This is because if the officer is caught red-handed, it will be easier to prove his guilt and take action against him. Additionally, catching the officer red-handed will send a strong message to other officers that corruption will not be tolerated.
However, it is also possible that the CBI may not be able to catch the officer red-handed. In this case, the CBI may need to wait for some more complaints about the officer to be sure about the matter. Once the CBI has gathered enough evidence, it can then take action against the officer.
Therefore, either course of action I or II could follow.