Answer:
They have a sense of self similar to that of humans.
Explanation:
Few animals such as apes, monkeys, elephants, and dolphins have shown that they have a sense of self. Generally this has been proved by the use of mirrors.
Here, the dolphins recognize the sounds as the names of their friends. They do not react to strangers' names. This means they recognized their own name. As they have associated themselves with a name they understand the concept of self.
Hence, the dolphins have a sense of self, similar to that of humans.
