Answer the following question given this paragraph: 

A common disorder of the ovaries is an ovarian cyst . A cyst is a sac filled with fluid or other material. An ovarian cyst is usually harmless, but it may cause pain. Most cysts slowly disappear and do not need treatment. Very large or painful cysts can be removed with surgery.


Q: What is the term for a sac filled with fluid or other material?

 Choices:

- blister

- lesion

- tumor

- cyst

A:
cyst
