Which of the following is a homogeneous mixture? 

Sugar solution 

The correct answer is option 2. Sugar solution.

A homogeneous mixture, also known as a solution, is a uniform combination of two or more substances. In the case of a sugar solution, it consists of sugar dissolved in water. The sugar molecules are evenly distributed throughout the entire mixture, creating a uniform composition. This uniformity is a characteristic feature of homogeneous mixtures, where the components are indistinguishable and have a consistent composition throughout the mixture. In contrast, a heterogeneous mixture, like a mixture of sugar, salt, and sand, would not have a uniform composition, and the different components would be visibly separated.