Which statement correctly describes the swap cache in the Linux memory model?

A.
It is an area in the swap file that maintains the number of page ins and page outs for every process.

B.
It contains the page entry table to record the addresses of in-memory pages that are not swapped out at all.

C.
It is an area in the RAM that is used to record the number of swap in and swap out operation for every page.

D.
It is an area in the RAM that tracks the pages that are swapped out and have not been modified since they were swapped out.