What describes a variable or expression that evaluates to either true or false?

• A. Address
• B. Theme
• C. Blog
• D. Boolean

Answer: (D)

A boolean is a data type that represents truth values, specifically true or false. Any variable or expression that can resolve to one of these two values is a boolean expression or boolean variable. This is essential for making decisions in code, since conditional statements rely on these true/false results to choose which path to take. The other terms describe non-truth-valued concepts: an address is a location, a theme is a design or subject, and a blog is a piece of online content. They don’t denote a value that can be true or false, so they don’t fit as descriptions of a variable or expression that evaluates to true or false. Therefore, the correct concept is Boolean.