Answer
The correct answer is:
(b) The water level is at the top of the glass but no water has spilled.
Work Step by Step
By Archimedes' principle, the weight of the water displaced by the ice cube is equal to the weight of the ice cube.
Let $V$ be the volume of the part of the ice cube that is below the water surface. If we filled this volume $V$ with water, the weight of the water would be equal to the weight of the ice cube. Therefore, when the ice cube melts and changes into liquid water, it will exactly fill the volume $V$.
Therefore, the water level in the glass does not change.
The correct answer is:
(b) The water level is at the top of the glass but no water has spilled.
