Never lie. Be confident. And even if the question asked could put you at risk of getting rejected, supplement your answer with something that could convince VO to issue you visa.
e.g. Are electives necessary to your course?
Ans1. No, they are not.
Ans2. No, they are not mandatory but I want to experience and learn from the best health care system of the world and hence I want to do this elective. I will return back to India after completing it since I still have pending course work here.
Ans 2 is better. why? Bcz not only it explains why you want to do something that is not necessary for your course work, but it also convinces VO that you will return to India since you still have pending course work that you need to finish in order to graduate.