What does this sign mean?

a. another lane of traffic will be merging with the one you are on.
b. the road you are traveling on ends ahead.
c. the road ahead makes a sharp turn.
d. drivers must proceed down the indicated path.

Option A.

Explanation:

Another lane of traffic will be merging with the one you are on, is the right answer.

In the context of traffic engineering, the zipper method or the late merge is a practice for merging traffic into a diminished number of paths. Operators in merging lanes are required to use both passages to drive to the lane discount duration and blend at that place, alternating shifts.

corrupt also means cruel