Ohio is an easy state, so don't fret. I would use the word "philosophical" for the reason. I'm guessing they are looking for more of a multiple choice answer...it's either medical, religious, or philosophical (which are the 3 waivers available in Ohio).
Mostly, they just are complying with state laws, and need to have it or the record on file. They don't personally care. In my personal experience with three older unvaxed kids, the only time I really had to throw down was once with a health dept. nurse (long story) and a pediatrician, who obviously makes a living off of hooking people to this fear mongering. I won both, and have three disease free kids, that have strong immune systems against everything, because I didn't vaccinate.
I'm never experienced any trouble with schools, day care or the like and once I found a good family doctor, we were good to go there too.
Don't stress it! Be far more concerned that he's growing up so fast! :)
And too, be aware of the numerous times you will be told something about vaccination that is entirely untrue. Over the course of your child's school career, you may have to be very well-versed in your state laws to be able to meet such ignorance head-on.
So I could just say:
Following below will be your state law re: exemptions.