Which statement can be combined with its converse to form a true biconditional?
A. If an angle is a straight angle, then its sides are opposite rays.
B. If the measure of an angle is 30, then it is an acute angle.
C. If a ray is the perpendicular bisector of a segment, then the ray divides the segment into two congruent segments.
D. If two lines intersect, then the two lines are not skew.