I have a teenager who is disabled, but he has mobility issues. He can ride his 3-wheeled bike really well, but it's slow, and not designed to keep up with family/friends. It's also really low profile, more designed for parking lots than streets.

I think the answer for him might be an electric tricycle that would allow him to ride to high school, carry his backpack, etc. It would also have enough power to go on real bike rides on our greenbelts. He is probably strong enough to operate a bike, but he lacks acceleration power (starting watts) and balance.

What is my best option?

Are you thinking something like this?

https://www.pedegoelectricbikes.com/product/trike/

Just using this one as an example.

Yes, thanks. We looked at se today with 2 wheels in front and one in back. The seats were more like chairs than traditional bike seats. Looks like the low end for the bikes is around $1000, and the battery motor adds another $1500. So, $2500 to $10,000+.