MBA is a better option for you..

I would suggest that you should first do your MBA, complete your studies first, get a masters degree (although it's not a compulsion for taking css exam).

During your studies you should keep a sharp eye on the current and international affairs, and read English newspaper. After completing your MBA, you can take css exam easily.

I would suggest that you should complete your professional qualification first, because CSS is a matter of luck and chance, you may or may not pass it..

Goodluck for your future endeavors
Regards,

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I hope our Wisdom will grow with our power, and teach us, that the less we use our power the greater it will be..