What is the most likely reason that della remains eager to give jim his gift after receiving her combs in “the gift of the magi”? della knows she will soon be able to benefit from the combs because her hair will grow back. della fails to realize that jim could purchase the combs only after selling his precious watch. della believes receiving the fob chain will make jim forget that he is upset about her hair. della recognizes that jim is not fond of carrying his watch on an inexpensive leather strap.