A student adds a tablespoon of sugar to a glass containing tea and ice cubes. The mixture is then stirred until all the sugar dissolves. Which observation is a clue that the student's final mixture is heterogeneous
A. Some ice cubes are floating in the tea
B. The sugar crystals are no longer visible in the tea
C. The mixture looks the same throughout
D. Some water droplets form on the outside of the glass
The subject is science

The correct option is;

A. Some ice cubes are floating in the tea

Explanation:

A heterogenous mixture is one that is made up of more than one clearly identifiable phase of matter (such as solid and liquid, liquid and gas, gas and solid, or solid, liquid and gas combined) and therefore having non-uniform composition, which varies from one section to another within the mixture.

Ice cubes which are solids being observable on the surface of the mixture provides clue that the student has made an heterogenous mixture.