I would choose their personality first and how the chemistry was with them but if I had to choose maybe the big company person? Only because Im studying to be an accounting consultant for large companies so we could relate on that lvl!
i'd have to find out what their personality is like first. you'd expect the stereotype that someone working in advertising is a bit cold and ruthless - eg. mad men - and that the primary school teacher is warm and loving. but there's nothing stopping it from being the other way around.
Probably the teacher. I imagine that anyone working in such a high position and for such a big company must have a certain amount of ruthlessness in their character. That being said, I've known some absolutely plebbish teachers as well. Tricky.