The correct option is; SUGAR DISSOLVING IN WARM WATER.
There are two types of change in chemistry; physical and chemical changes.
A physical change is a type of change in which no new substance is formed while a chemical change is a type of change in which a new substance is formed.
Dissolving sugar in warm water is a physical change because no new substance is formed and the sugar can easily be recovered from the water by evaporating the water.