When a traffic signal displays a green arrow pointing left, you may:

Correct answer: C – Turn left cautiously after yielding to lawful traffic and pedestrians still present
A green arrow permits you to enter the intersection for the movement shown by the arrow. You must still yield to pedestrians and bicyclists lawfully in an adjacent crosswalk and to other traffic lawfully using the intersection. A left-pointing arrow does not authorize you to continue straight unless another signal permits that movement.
Source: 625 ILCS 5/11-306(a)(2) — Traffic-control signal legend



