Sir, Please could you tell me that in a question if it asks as to compare currency futures with fra, which exercise price should we use?? Should we try all 3 and give our opinion or is there something else I am missing?
I think what you really mean is comparing options (where there are several exercise prices to choose from).
Ideally you would try all available exercise prices and then give an opinion. However if you are short of time then just using one exercise price proves you know what is happening and will get you most of the marks.