What is unusual about the way the women are playing the piano?

Explanation:

What is unusual about the way in which these women are playing the piano is that they are playing with their opposite hands, which is, one of them plays with the left and the other one does it with the right hand, but as they are playing togetherm they are like an only person playing the instrument.

c. with one finger is the answer

search it up on google or think from your brain make it work harder.