The answer is C, a perpedicular bisector. The distances of the mark along the given line are equidistance. Where the x is located, where the two dashes would intersect is where a 90 degre angle to the line would pass through.
If Jana has to walk 2 blocks north to get to Kyle's home, then 3 blocks south to get to school, this means that she has just retraced the 2 blocks she walked to get to Kyle's home.
So the school is just 1 block south of Jana's home.