What are you required to do according to the following road sign?

1. Correct answer: Continue driving, pay attention to vehicles merging from your left.
2. Change lane and allow approaching vehicles from the right to merge.
3. Give right-of-way to vehicles merging from your right.
4. Slow down and give right-of-way to vehicles merging from your right.

WhyOn the sign your road is the main one, and a minor road merges into it from the left. You do not need to give way; keep driving but watch for vehicles merging from the left.