Re: what religio would you choose if....
Children are born into religions. They aren't mature enough to understand religions properly, so the real choice is made by them when they've grown old enough to understand. This is pretty much the same as a person who had no cutural/religious background. When that person has grown to mature age, the real choice will be made then.
This goes for the Muslims aswell. Many young Muslims (teens), just follow what their fathers had followed, without actually looking into what Islam really is, and so they never realize the mistakes which they make.
I am not a Muslim because my ancestors were Muslim. I am a Muslim because I read & understood the contents of the Quran, and signs therein revealed by Allah, to me, proved that he is the One.