Final answer:
Among the options given, milk of magnesia is an example of a base because it has a pH greater than 7, specifically a pH of 10.5, indicating its basic nature.
Step-by-step explanation:
The question seeks to identify an example of a base from a list of substances. From the information provided, we can determine that milk of magnesia with a pH of 10.5 is basic, as it has a pH greater than 7. Milk of magnesia contains the compound magnesium hydroxide, Mg(OH)2. Pure water is neutral with a pH of 7, and wine, with a pH of less than 7, is acidic. Therefore, among the options given, milk of magnesia is an example of a base.