Final answer:
The correct option is to look in the rearview mirrors, over your shoulder, and check traffic ahead to ensure full awareness of your surroundings while driving.
Step-by-step explanation:
To check traffic ahead, in both rearview mirrors, and over your shoulder when driving, the correct action to take is option 4: Look in the rearview mirrors, over your shoulder, and check traffic ahead. This comprehensive approach ensures that you are aware of your surroundings on all sides of your vehicle. Checking rearview mirrors provides a view behind your car, but it is important to also look over your shoulder to check for blind spots that your mirrors cannot cover. Furthermore, being attentive to traffic ahead helps in anticipating any necessary maneuvers or reactions in response to the road conditions or traffic behavior.