If You Were to Buy One Peach Tree and One

If you were to buy one peach tree and one apple tree from the Stark Bros. fruit trees and landscaping catalog in two separate orders, you would pay a total of $109.99. However, if you order the peach and apple tree together in the same order, you pay only $89.99 each. When selling the two trees together for a reduced price, what pricing strategy does Stark Bros. employ?

A) product-line pricing
B) prestige pricing
C) price lining
D) discount pricing
E) bundle pricing