Answer:
C: The solution has become saturated.
Step-by-step explanation:
The sugar is not dissolving in the tea because the solution has become saturated. Saturation occurs when the concentration of solute (sugar) in a solvent (tea) has reached its maximum limit, beyond which no more solute can dissolve. At this point, the undissolved solute will settle at the bottom of the container. In this case, the tea is unable to dissolve any more sugar, so it stays at the bottom of the glass.