Concept:An increase in thermal energy causes a solid to change into a liquid.
Explanation:When thermal energy is added to a solid, the particles gain more kinetic energy.
The particles vibrate more vigorously and eventually overcome the forces holding them in fixed positions.
The solid then changes into a liquid.
This change of state from solid to liquid is called melting.
Evaporation is a liquid-to-gas change, so it is not correct here.
Freezing is a liquid-to-solid change that releases thermal energy.
Condensation is a gas-to-liquid change that also releases thermal energy.
Since the question specifies a solid gaining thermal energy, the correct change of state is melting.
Answer:A. melting