Answer:
"If a line is a segment bisector, then it intersects the line segment at its midpoint."
Step-by-step explanation:
We have to find the proper biconditional statement for the conditional statement "If a line intersects a line segment at its midpoint, then it is a segment bisector." from the given four options.
I think the proper biconditional statement of the above conditional statement will be the first one i.e. "If a line is a segment bisector, then it intersects the line segment at its midpoint."
Therefore, option A is correct. (Answer)