While preparing to run a marathon, Amelia created a training schedule in which the distance of her longest
run every week increased by a constant amount. If
Amelia's training schedule requires that her longest
run in week 4 is a distance of 8 miles and her longest
run in week 16 is a distance of 26 miles, which of the
following best describes how the distance Amelia
runs changes between week 4 and week 16 of her
training schedule?