What does this traffic sign mean?

What does this traffic sign mean?

1. All vehicles must stop or park on the left
2. All vehicles are prohibited from turning left at the junction ahead
3. All vehicles must turn left at the junction ahead

Correct answer

All vehicles must turn left at the junction ahead

This is the correct answer for the Cambodian driving theory test. Questions are drawn from the official Ministry of Public Works and Transport sign library and road rules.