cgc3-
Good question, which MAY create a different answer depending upon.......
Why does your son think he would never attend a particular school? Is it a school that he knows has too high academic standards? Is it a school that is too big? too small? Does not offer his major? He doesn't like the baseball program?
Depending on the answer to these questions could mean that MAYBE he doesn't know enough about the school and should try to find out more about it before saying he would never attend there.
In the end, if you don't respond, the coach will figure he is not interested and will probably take him off his mailing list.
If, in the final analysis, there is no way your son would attend the school in question, option B appears to be a very sound, mature approach. There is a possibility in this scenario the coach may ask why he is not considering his school as an option. Depending on the reasons, and whether or not he wants to share them with the coach, this could create an awkward moment.....food for thought anyways...
GOOD LUCK!!!!