It depends on what you enjoy doing and what would get the best results that you wanted out of you
Typically people can be very broadly classified in 2 categories
1-People People - These are extroverts that enjoy being around other people, that are gregarious, don't think too much before they say some thing, these guys tend to be good sales people and good people leaders, that emotionally connect rather than worry about always being correct and accurate
2-Analytical or technical people - these are introverts, rather very good at building a technical skill, meaning they enjoy taking a subject, attaining some level of mastery in the subject by themselves and enjoy doing that thing fully immersing themselves in it, typically these people tend to be the subject matter experts, technology architects, accountants, finance experts etc, these are emotionless people that are focused on what is correct and accurate, highly mathematical and technical
Also it doesn't mean a person is 100% introvert or 100% extrovert, people have diff degrees of introvert and/or extrovert qualities depending on what they learned growing up in different circumstances.
Pursuing MIS would put you in category 2, pursuing MBA would put you in category 1 , where as entrepreneur you will have to be flexible and switch between the two often. At one point you have to stand up in front of people and do a great sales pitch, at other times you have to roll up your sleeves, bury your head into a computer and solve a bug.
I would pick the one that I enjoy doing, which means you need to figure out what you would enjoy doing then also talk to people that have done those two things or three things and get a feel for what your life will be if you choose either one.
But the most challenging and the rewarding one is being an entrepreneur and smart people, even super smart people fail in their first attempt.
Good luck with your decision.