Answer the following question given this paragraph: 

Mother of pearl is also known as nacre. Nacre is the iridescent inner shell layer. It can be found in buttons, watch faces, knives, guns, and jewelry. It is also used to decorate various musical instruments.


Q: What is another name for mother of pearl?

 Choices:

- pigment

- enamel

- calcium

- nacre

A:
nacre
