Which answer is the best correction of the sentence fragment?

David wants to buy a bike. Or a scooter.

Responses

David wants to buy a bike, or he wants a scooter to buy.

David wants to buy a bike, or he wants a scooter to buy.,

David wants to buy a bike or a scooter.

David wants to buy a bike or a scooter.

David wants to buy: a bike or a scooter.

David wants to buy: a bike or a scooter.,

David wants to buy a scooter. Or a bike.

David wants to buy a bike or a scooter.