Which of the following is true according to the passage?

• A. Bottlenose dolphin is the only species that has the ability to learn and to combine a large number of referential symbols.
• B. Bonobos cannot learn and combine large numbers of symbols or gestures that stand for objects and actions.
• C. Scientists say that dolphins and chimps should be set apart from other nonhuman animals.
• D. Unlike other cetacean species, bottlenose dolphins cannot recognise their reflection in the mirror.
• E. Scientists still argue that dolphins should not be released from captivity.