The most aggressive of the four eastern－slope species is the lodgepole chipmunk, a feisty

The most aggressive of the four eastern-slope species is the lodgepole chipmunk, a feisty rodent indeed. It actively prevents alpine chipmunks from moving downslope, and yellow pine chipmunks from moving upslope. There is logic behind the lodge-poles aggressive demeanor. It lives in the cool, shaded conifer forests, and of the four species, it is the least able to tolerate heat stress. It is, in other words, the species of the strictest habitat needs: it simply must be in those shaded forests. However, if it shared its habitat with alpine and yellow pine chipmunks, either or both of these species might outcompete it, taking most of the available food. Such a competition could effectively eliminate lodgepole chipmunks from the habitat. Lodgepoles survive only by virtue of their aggression.

According to paragraph 6, why is the lodgepole chipmunk so protective of its habitat from competing chipmunks？

A．It has specialized food requirements.

B．It cannot tolerate cold temperatures well.

C．It requires the shade provided by forest trees.

D．It prefers to be able to move between areas that are downslope and upslope.

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