Which of the Following Is True About Mortgage-Backed Securities

Which of the following is true about mortgage-backed securities
I. They aggregate individual home mortgages into homogeneous pools.
II. The purchaser receives monthly interest and principal payments received from payments made on the pool.
III. The banks that originated the mortgages maintain ownership of them.
IV. The banks that originated the mortgages continue to service them.

A) II, III, and IV
B) I, II, and IV
C) II and IV
D) I, III, and IV
E) I, II, III, and IV