【单选题】

While forensic scientists commonly rely on fingerprints to help identify a

Line person, it is not possible to use the same kind of technology with other species
of mammals. Recently, however, a group of researchers from Tokyo developed a
device that allows them to identify individuals of the endangered Ganges River
(5) dolphin species. This underwater acoustic device measures the clicking sounds
produced by the creatures and helps with identification and tracking, since each
sound is as completely unique as a fingerprint.
Ganges River dolphins are rare in that, unlike the majority of their
counterparts, they live in rivers and lakes rather than oceans. The species is blind
(10) and uses clicks to send out sonar pulses for guidance and to find fooD、In the past
few decades, their numbers have decreased by 50 percent, because of fishing net
entanglement, human predation, pollution, construction, or a combination of
these factors. With this new acoustic technology, scientists hope to get a better
idea of how many of these dolphins still exist, as well as their migration patterns
(15) and feeding habits. In turn, this information may help scientists protect and
conserve this unique species.
The passage supplies information for answering which of the following questionsA．How do the remaining Ganges River dolphins still exist
B．What is the primary use of the new underwater acoustic technology
C．Why do Ganges River dolphins make their homes in rivers and lakes
D．How does the underwater acoustic technology work
E、Can the new underwater acoustic technology be used in identifying and tracking other species of dolphins