Hi Tracy đ€
Sentence âBâ is correct (âI think I might have been driving too fastâ). Sentence âCâ is in the âpast tenseâ, and sentence âBâ uses the âpast participleâ.
So why âBâ and not âCâ? As a native speaker, when I read this dialogue, sentence âBâ sounds much more natural.
We should choose the âpast participleâ option when we are talking about a past event that can be linked to another time (usually the present).
In your example, the two people are probably talking about all aspects of this car accident (including âpresentâ consequences from the accident such as current injuries, car damage, dealing with car insurance, etc.). Even though the âfast drivingâ is finished, the âfast drivingâ is now linked to present circumstances.
I hope this helped đ€đ
Nicky Ann