Explanation:

Horizontal Curves:
- Horizontal curves are sections of the road that are not straight and have a curved shape.
- These curves are designed to allow vehicles to smoothly transition from one direction to another without abrupt changes.

Centrifugal Force:
- Centrifugal force is the apparent outward force experienced by an object moving in a curved path.
- It is a result of the inertia of the object trying to keep it moving in a straight line while the object is being forced to move in a curved path.
- In the case of vehicles on a horizontal curve, centrifugal force pushes the vehicle away from the center of the curve.

Lateral Friction:
- Lateral friction is the friction between the tires of a vehicle and the road surface in the lateral direction (sideways).
- It is responsible for providing the necessary grip between the tires and the road, allowing the vehicle to maintain control during turns.

Skid:
- Skidding occurs when the lateral friction between the tires and the road is not sufficient to counteract the centrifugal force.
- In this situation, the tires lose grip with the road and the vehicle slides or skids in the direction of the centrifugal force.
- Skidding can result in a loss of control and can be dangerous, especially at high speeds.

Explanation of the Answer:
- The answer to the question is option 'A' - skid.
- When the centrifugal force exceeds the lateral friction between the tires and the road, the tires lose grip and the vehicle skids.
- This means that the vehicle is sliding or slipping in the direction of the centrifugal force instead of following the intended path of the curve.
- Skidding can lead to a loss of control and potentially result in an accident.
- Therefore, it is important for drivers to be aware of the dynamics of their vehicle on curved sections of the road and adjust their speed accordingly to prevent skidding.