Understand why Bank do this

The purpose of this investigation is not to find trouble for you, but to cover the a$$ of the bank so that the government will not accuse the bank for helping illegal activity.  

Just answer whatever you feel like, although I suggest truthfuly, but no consequences if you don't.  Bank just file this paper in your file. In case you are arrested later by FBI for some federal crime, and the bank will find this paper and tell FBI the bank did its job and is not an accomplice.