According to the passage, why are the studies that conclude that dolphin intelligence is "

According to the passage, why are the studies that conclude that dolphin intelligence is " somewhere between that of a dog and a chimpanzee" not correct？

A．The human method of drawing comparisons is not relevant to animal intelligence.

B．Dolphins have actually been shown to be much more intelligent than chimpanzees.

C．The studies were not conducted according to standard research methods.

D．Dolphins do not typically demonstrate conditioned responses for humans to observe.

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