C.
that one year mark is a formality. but the reason it's recommended is because most children only need a dentist at that age because of an injury to their teeth, after a fall or an accident. it's just to familiarize the child with the dentist so that it's not as traumatic and new a situation if they should have to go in an emergency situation.
that said, I waited until close to two years to take my son, he has an extra tooth that I wanted to get checked out. it was a great office, of course it's the only pediatric dentists office I've ever been in, but I thought it was nice. the dentist used grape flavored gloves. toys were everywhere, and they encouraged/wanted me to come with him. after the exam (no xrays, he just felt around and looked in his mouth), they let my son pick out a toy to take home. it was a positive experience for him. let me know if you would like the name of the dentist, I'll look it up for you.