What should you do if you encounter a flashing yellow traffic light?

Answer: B — Proceed with caution.

If you encounter a flashing yellow traffic light, it means that you should proceed with caution. This is because a flashing yellow light is used to indicate caution and that drivers should slow down and proceed carefully through the intersection. Option A is incorrect because stopping and waiting for the light to turn green is reserved for a solid yellow light, not a flashing one. Option C is incorrect because yielding the right-of-way should only be done at a stop sign, not a flashing yellow light. Option D is incorrect because it goes against the purpose of a flashing yellow light, which is to indicate caution. It is unsafe to speed up and try to quickly clear the intersection when encountering a flashing yellow light.