The answer is actually not that difficult: DON'T take your goals out of the motivation letter. The reasoning is straightforward - without your career goals you have no reason to pursue an MBA!!!!
Sooooo even if they ask it elsewhere, your actual career goals will nonetheless be the core of this essay. Now if you have already elaborated in detail in the short question, you don't have to repeat yourself, but still the specific goals you present, the past experience you have which will lead to them, and the chain that will bring you towards your goals are the most important parts of this letter.
If you like the post, give it a KUDOS!