Which of the following represents the state of neutral equilibrium? A. A cube resting on one edge B. A smooth cylinder lying on a curved surface C. A smooth cylinder lying on a convex surface D. None of the above

The correct answer is: A. A cube resting on one edge.

A cube resting on one edge is in a state of neutral equilibrium. This means that if the cube is disturbed, it will not return to its original position. Instead, it will continue to rotate until it comes to rest on one of its faces.

A smooth cylinder lying on a curved surface is in a state of unstable equilibrium. This means that if the cylinder is disturbed, it will not return to its original position. Instead, it will continue to roll until it comes to rest on one of its sides.

A smooth cylinder lying on a convex surface is in a state of stable equilibrium. This means that if the cylinder is disturbed, it will return to its original position.

In conclusion, the only option that represents the state of neutral equilibrium is A. A cube resting on one edge.