I didn't mean to diss Bohr at all - I was trying to be brief in the short answer as that's what's asked for. He's of course a giant of physics and I did say this question is better directed at a physicist rather than a chemist - I wonder a bit why there isn't a physics section here. If my answer was a little inaccurate with regards to models then thanks very much for pointing that out.
As for level of difficulty I entirely disagree. If someone is asking about the Bohr model then that's not school stuff at all (in my experience) and so I'll treat the question at the level it is asked at. The Bohr model is all I was taught at school in the late 1980s with only a very slight touch on quantum theory (with regard to atomic structure at least). His name I'm fairly sure, and his detailed theory was certainly taught to me in my first term at UNiveristy - in fact we did a full detailed derivation of the wavefunctions of the hydrogen atom using Schroedinger's equation and spherical harmonics in that term (though that drove my tutorial partner at the time to quit chemistry!)
Depends who's reading - how are we to know - why not give answers that may satisfy more intelligent students. I did all three of these reaction types when I was at school.
What does regioselectivity mean?