I am from science background which optional subject is best for IAS preparation
Science thik rahega
The subject that appears more interesting, could be your optional.
Geography is best in my view
Go for the subject u have more interest in.
Try reading some of your decided optionals...
N u'll know thats wats optional is penetrating through your mind...
Optionals are required but once you clear your main hurdle that is the prelims..then you are almost set for the main exams. That time shall be quiete helpful for you to decipher what you have expertised in. As a vox populi ; Public Administration is the most lauded subject.