Go to all three, chat to instructorss and students, stick around and have a coffee, if possible have a trial lesson. That way you get the feel of the place.
Check that you can have the same instructor most of the time, and that YOU can decide which instructor you want.
Check aircraft availability. Would you usually have to book weeks and weeks in advance?
If you haven't already, ask if they charge on engine running time, brakes off to brakes on, or tacho time. It can make quite a difference...though I wouldn't let cost be your main consideration.
Only choose option C if you can stay nearly by and do an intensive course. You can't drive for a few hours and still be in a fit state to do flying training.
If all else is equal, choose A. Being close to home is great. There will be times when lessons are cancelled at the last minute, and not having a long drive is very useful.
B sounds lovely. But make sure you're going to get lots of practice on the radio, which is often the weakest area for new PPLs.
To summarise - A or B, whichever feels right; only pick C if you can stay locally to do the course.