Once you finish overtaking the truck, can you continue driving in the left lane?

Once you finish overtaking the truck, can you continue driving in the left lane?
A)No, you must drive in the right lane.Correct
B)No, because the left lane can only be used for overtaking.
C)Yes, because on a motorway you can drive in any lane.
Unnecessarily staying in the left lane can obstruct the flow of traffic and increase the risk of accidents, as it may prevent other faster-moving vehicles from overtaking safely. Therefore, the general rule is that after overtaking, if you are not going to continue overtaking, you must return to the right lane to allow other vehicles to pass and maintain a safe and efficient traffic flow.
Answer b) is not correct, since the left lane is not only used for overtaking; there are situations in which you can drive in it, such as to take an exit on that side or if the right lane is obstructed or there is some obstacle.