The correct answer is:
D) truth value.
Explanation:
The values "true" and "false" are used to describe a conditional statement's truth value. The hypothesis of a conditional is the part after "if," and the conclusion is the part after "then"; while true or false will describe these, that is not the definition.
A counterexample is an example that disproves a conditional statement; again, while true or false will describe this, they are not the definition