What solution is identified as more basic?

Milk of magnesia is identified as more basic compared to the other options. This is due to its composition, which primarily includes magnesium hydroxide, a compound that acts as a strong base in solution. When dissolved in water, it increases the concentration of hydroxide ions (OH⁻), leading to a higher pH, characteristic of basic solutions.

In contrast, lemon juice and grape juice are acidic due to the presence of organic acids such as citric acid and tartaric acid, respectively, which result in a lower pH. Pure water is neutral, with a pH of around 7, indicating neither acidic nor basic properties. Thus, milk of magnesia stands out as the most basic of the given choices, and its alkaline nature is typically utilized in medicinal contexts to neutralize stomach acids.