Why does water level fall initially after it is heated

The volume of water is yet to absorb the heat in extending, for which the liquid level in the container falls initially. When a sufficient amount of heat is able to transfer through container in raising the temperature of water throughout the volume, the volumetric expansion of water ie more than that of the solid container takes place. The level of water in container rises up till the expanded water over flows off the container.

A., d., and f i think