Which two statements are true about the database buffer cache?

Which two statements are true about the database buffer cache? (Choose two.)

A.
A buffer can be written to by many processes at the same time.

B.
A buffer containing a block that is identical to the block on disk is called free buffer.

C.
A buffer containing a block that is being accessed by a process is called dirty buffer.

D.
A buffer available to be overwritten with a different database block at any time is called a dirty
buffer.

E.
A buffer can contain a different version of a block that is available in a different buffer of the
same cache.