same here , I have done my MBA and will have to start study for 2013 exam, and I think I can and you can also do this , so don't worry and will do hard work !!!IN SHA ALLAH will do it.
my optional subs choices are
Business administration = 100
zoo/ chem / phys (any one) =200
agriculture and forestry =200
international relation = 100
may be WILL change one of the above option with any other!!!