What does a yellow sign indicating that the road ahead may be slippery mean?

Answer: C — Proceed with caution

A yellow sign indicating that the road ahead may be slippery is a warning for drivers to proceed with caution. This type of sign is intended to alert motorists to the potential for hazardous conditions, such as wet, icy, or otherwise slippery surfaces that could affect vehicle control. By advising caution, it encourages drivers to remain vigilant and be prepared for sudden changes in driving conditions. While it may be beneficial to also increase following distance or adjust speed, the primary response prompted by the warning sign is to approach the area carefully. This allows drivers the opportunity to evaluate the road conditions and adjust their driving behavior accordingly to maintain safety.