Final answer:
At a solid's melting point, the kinetic energy overcomes the intermolecular forces, initiating a transition from solid to liquid without raising the temperature further until the solid is completely melted. So the correct option is D.
Step-by-step explanation:
When the temperature of a solid reaches its melting point, the kinetic energy of the particles within the solid is sufficient to overcome the intermolecular forces holding the particles in their rigid structure. The process of melting involves absorbing kinetic energy, which causes the particles to vibrate more vigorously until the organized structure begins to break down, transitioning the solid to a liquid state.
At the melting point, the temperature of the substance does not increase until the entire solid has melted into a liquid. This is because the input of energy is used to break the bonds between the particles, rather than to increase their kinetic energy. Therefore, the correct answer to the student's question is (D) the kinetic energy exceeds the intermolecular forces.