C.
Start brushing as soon as they have teeth. Use fluoride free toothpaste until they can spit it out (usually around 3). Most pediatrian recommend going to the dentist at 3. However, most pediatric dentist recommend starting at 2 (which is what we did) because they get used to it sooner. Now my daughter who is 3-1/2 goes back all by herself & has even had x-rays. It is also important to go early if they have any habits such as thumb sucking. Best of luck!