Which statement best describes the relationship between comprehension and extension?

• A. They are both mental constructs
• B. They are inversely related
• C. They have no relationship
• D. They are always opposites

Answer: (C)

Comprehension and extension describe two sides of a concept’s meaning, and they move in opposite directions. Comprehension is about the attributes or properties that define a term; extension is about all the things that the term applies to. If you add more attributes to specify the term, you make it more particular, so fewer things fit—that shrinks the extension. If you loosen the attributes and allow more things to fall under the term, the extension grows, but the term becomes less specifically defined, so the comprehension is broader only in a loose sense but less informative. For example, “triangle” covers a large extension (all triangles) with relatively simple defining features, while “isosceles triangle” narrows the extension (only triangles with two equal sides) and adds more defining attributes. This inverse relationship shows why the statement that there’s no relationship doesn’t fit; comprehension and extension are linked through this opposite-direction connection.