This sign warns you of:

The sign indicates slippery conditions when wet, which is an important warning for drivers. When roads are wet, such as during rain or after a shower, the surface can become slick, especially in certain conditions, such as when oil and water mix. This can lead to reduced traction between the tires and the road, increasing the risk of losing control of the vehicle. Recognizing this warning helps drivers adjust their speed and driving behavior to maintain control and reduce the likelihood of an accident.

In contrast, the other options pertain to different scenarios: a tow-away zone signifies a location where vehicles may be removed if parked improperly, a steep downgrade sign warns drivers about upcoming steep declines that may require reduced speed or gearing down, and a roadwork sign alerts drivers to construction activity or changes in road conditions that may require caution. Each of these also serves a critical purpose for safe driving, but in this case, the sign specifically relates to the caution needed for wet conditions.