Shreya left the hardware store and drove toward the train station. One hour later Jill left driving 13 km/h faster in an effort to catch up to her. After five hours Jill finally caught up. What was Shreya's average speed?​

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.

i think the answer would be c