题目内容：
根据以下内容回答题： There are some 65 species of New World monkeys. Many of these have very useful anatomical adaptation lacking in their Old World counterparts: the prehensile tail.
And in a few species the gripping tail has developed to such an extent that it actually has “fingerprints” on the tip. While of course a tail is not equipped with fingers, it can sometimes be even more useful than an arm or a leg. A spider monkey’s tail, for instance, is longer than its head and body combined, and is frequently used instead of a hand to grasp distant objects. Other monkeys less fortunate are forced to relegate at least one limb to support while they feeD． Whereas monkeys endowed with prehensility can hang by their tails while they feast with both hands and feet. A few New World monkeys have also evolved arms and shoulders that are suitable for swinging hand over hand through the tress like the Asiatic Gibbons.
The passage mainly discusses ____. A．certain evolutionary advantage of New World monkeys
B．feeding habits of the spider monkey
C．the development of arms and shoulders in New World monkeys
D．some anatomical adaptations of Asiatic Gibbons
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