Science

In improvement exam only those subject marks get changed, which you are going to write again, other remain the same.

If yo are job inclined, you must first complete your graduation simply by doing B.Sc in any subject (Physics has a good scope). If you are not interested in B.Sc, you can try for pharmacy. If you are not interested in pharmacy as well as in other profession related to it, you can let me know. I will suggest you some other smart options for jobs.
Good luck.

I depends upon your interest and you must see that the books of which subject are easily available in your city.
But if you ask me about which subject to choose, I would prefer sociology or public administration because these are easy subjects and easily understandable. Besides, anthropology is also a good and competition is also less for it.
But again, your choice must completely depend on your interest.