The researchers tested Happy, Maxine and Patty, three elephants at the Bronx Zoo. They put

an 8-foot-square mirror on a wall of the animals' play area (out of the sight of zoo visitors) and recorded what happened with cameras, including one built in the mirror.

The elephants used their long noses to find what was behind it, and to examine parts of their bodies.

 Of the three, Happy then passed the test, in which a clear mark was painted on one side of her face. She could tell the mark was there by looking in the mirror, and she used the mirror to touch the mark with her long nose.

Diana Reiss said, "We knew elephants were intelligent, but now we can talk about their intelligence in a better way."

1. What can mirror tests tell us about animals?

    A. Whether they have large brains.

    B £®Whether they have self-awareness.

    C. Whether they enjoy outdoor exercises.

    D. Whether they enjoy playing with mirrors.