B. is slightly crooked when pressing the pedals
Body positioning while driving is to maximize control over your vehicle, comfort, and ensure that you don't suffer from back pain due to incorrect sitting posture.
To do this, make sure your bottom is firmly touching the back of the seat. Your seat should be raised high to give yourself maximum visibility and pulled back only enough, so that your knee is still slightly crooked when pressing down on the pedals.
Let me emphasize that you must make sure your seat is pulled far enough forward, so you can fully press the accelerator and the brake pedal, while still having a slight bend in the knee.
