Answer:
Option D.
Step-by-step explanation:
A biconditional statement are the statement in which both parts have the same truth value. It is written in the form of "p if and only if q".
First statement: A whole number is even if and only if it is divisible by 2.
This statement is a biconditional statement because it is the definition of even numbers and have the same truth value.
Second statement: A whole number is odd if and only if the number is not divisible by 2.
This statement is a biconditional statement because it is the definition of odd numbers and have the same truth value.
Third statement: An angle is straight if and only if its measure is 180.
This statement is a biconditional statement because it is the definition of straight angle and have the same truth value.
Fourth statement: A ray is a bisector of an angle if and only if it splits the angle into two angles.
This statement is not a biconditional statement because if a ray splits the angle into two angles, then it is not necessary that it is a bisector.
Definition of bisector: A ray is a bisector of an angle if and only if it splits the angle into two congruent angles.
Therefore, the correct option is D.
