阅读理解三Questions 11 to 15 are based on the following passage. Most of us have seen a dog staring at, sometimes snarling at, and approaching a reflection of itself. For most animals, seeing their own image in a mirror acts as a social stimulus. But does the dog recognize itself, or does the reflection simply signal a potential companion or threat This question is interest for a number of reasons. Apart from curiosity about the level of animals’ understanding, research on self-recognition in animals has several benefits. It provides some insight into the evolutionary significance of this skill of self-recognition and into the level and kinds of cognitive competence that the skill requires. Such research also indicates the kinds of learning experiences that determine the development of self-recognition. In addition, work with animals fosters the use of techniques that are not dependent on verbal responses and that may therefore be suitable for use with preverbal children. The evidence indicates that dogs and almost all other nonhumans do not recognize themselves. In a series of clever experiments, however, Gallup has shown that the chimpanzee does have this capacity. Gallup exposed chimpanzees in a small cage to a full-length mirror for ten consecutive days. It was observed that over this period of time the number of self-directed responses increased. These behaviors included grooming parts of the body while watching the results, guiding fingers in the mirror, and picking at teeth with the aid of the mirror. Describing one chimp, Gallup said, "Marge used the mirror to play with and inspect the bottom of her feet; she also looked at herself upside down in the mirror while suspended by her feet from the top of the cage; she was also observed to stuff celery leaves up her nose using the mirror for purposes of visually guiding the stems into each nostril." Then the researchers devised a further test of self-recognition. The chimps were anesthetized and marks were placed over their eyebrows and behind their ears, areas the chimps could not directly observe. The mirror was temporarily removed from the cage, and baseline data regarding their attempts to touch these areas were recorded. The data clearly suggest that chimps do recognize themselves, or are self-aware, for their attempts to touch the marks increased when they viewed themselves. Citing further evidence for this argument, Gallup noted that chimpanzees with no prior mirror experience did not direct behavior to the marks when they were first exposed to the mirror; that is, the other chimpanzees appeared to have remembered what they looked like and do have responded to the marks because they noticed changes in their appearance. The purpose of the experiment introduced in the last paragraph is______.

A. to prove that the chimps are not self-precognitive
B. to prove that the chimps have the ability to remember their own appearance
C. to prove that the chimps have realized that the figures they see in the mirrors are themselves
D. to prove that the chimps are non-human