The correct choice that indicates that the line passing through AB is the perpendicular bisector of the line passing through CD, given that they intersect at point P, is:
B. line segment AP ≅ line segment BP
This choice indicates that segment AP is congruent to segment BP, which is a requirement for line AB to be the perpendicular bisector of line CD. When segment AB bisects segment CD at point P, it indicates that point P is the midpoint of line segment CD, while also being perpendicular to it.