AI is a technology that can do thing that humans are doing. So in future humans don’t have to these AI will do it for us.
I would say two car length rule. I am not sure what the official license rule is or if it has been changed, but originally the rule was 3 seconds usually depending on how fast the car is going. The faster you are going, the longer it takes to stop. So two-car length rule would probably be the best choice. Definitely not A.