When you see a flashing yellow signal at an intersection you should:

Answer: B — Slow down and proceed with caution

A flashing yellow signal indicates caution and requires drivers to slow down and proceed with caution. Coming to a complete stop would not be necessary unless there is conflicting traffic. Increasing speed and going ahead would be dangerous as drivers must be prepared to stop if needed. Honking the horn is not necessary and can cause confusion for other drivers. Therefore, the correct answer is to slow down and proceed with caution.