Namely the one where parents argue that it's far too dangerous for their children to ride bicycles.
Here's what I say.
One day, your child will turn 16. And they will need to get back and forth to school, practice, part-time jobs etc. As we both know, the high school driving years are probably the most dangerous years for young people and the most worrisome for parents. Wouldn't it be better if they could hold off on driving until they were a little bit older? Well, the way to make that happen is for them to have an way of getting around that doesn't involve being behind the wheel of a car. And the best way for that to happen is if they can easily and efficiently get around on a bike. For that, it's best that they start riding at a very early age and learn that you can get from a to b as easily on a bike as anything else.