On which surface (ground or marble) will thermal energy be reflected more?

The thermal energy will be more reflected by the surface of the marble.

Explanation:

The thermal energy is the energy produced by the heat. Marble is a good conductor of heat. In the summer, you feel cold when you touch marble.  

The ability of the material at which the heat is transferred is called thermal conductivity.

Higher the thermal conductivity of the material, more will be the heat transferred. The thermal conductivity of the marble is more than the surface of the ground.

Therefore, the thermal energy will be more reflected by the surface of the marble.