What type of data can only take one of two values, typically TRUE or FALSE?

The correct choice refers to a data type known as Boolean, which is specifically designed to represent one of two possible values: true or false. This binary nature is fundamental to how Boolean values function, especially in programming, logic, and decision-making processes. Boolean data types are often used in conditional statements or to represent states that can only be one of two options, such as "light on" (true) or "light off" (false).

Other data types listed have broader ranges: integers can represent whole numbers, real numbers can represent decimals and fractions, and strings consist of sequences of characters which can form text. Each of these data types can convey much more complex information compared to the straightforward dichotomy of truth values that a Boolean provides.