Final answer:
Before every lane change, you should signal your intentions, check your mirrors, and check your blind spots. The correct approach is to do all of these steps each time to ensure a safe maneuver. Hence, the answer is D - do all of the above.
Step-by-step explanation:
Before every lane change, the correct and safe procedure involves several critical steps: Firstly, signal your intentions to inform other drivers of your intended move. Next, check your mirrors to assess the traffic behind and to the sides of your car, which provides an overview of the general traffic situation surrounding your vehicle. Finally, always check your blind spots by looking over your shoulder into the lanes beside you, where vehicles might be hidden from view in your mirrors. Each of these steps is essential for executing a safe lane change and must be done in sequence. Failing to do any of these could result in a collision with other road users who may not be visible if one relies only on mirrors. Therefore, the answer to the question is D - do all of the above.