When on a two-lane road, you should use the left lane:

Answer: A — To pass other vehicles

When on a two-lane road, you should use the left lane to pass other vehicles because it provides you with a better view of the oncoming traffic and gives you more space to safely overtake the other vehicle. It is also important to remember to only use the left lane for passing and then move back into the right lane when it is safe to do so. Using the left lane for purposes other than passing, such as parking or turning left, can be dangerous and impede the flow of traffic. Additionally, using the left lane for any reason other than passing may result in a ticket or fine. So remember, the left lane is for passing only.