Hi. Your question is very pertinent to most young students today who are at crossroads in taking a career decision. I fully agree with the others that at first you need to be very sure as to why you have made the choice. That itself will answer your next question probably on the toughest decision you have made so far!! If you are convinced with your answer only then will you be convincing enough to the world. All the very best to you.
Zenobia
Zenobia