What is the difference between a mortgage and a ​mortgage-backed security​?
a. no interest is paid on​ mortgage-backed securities, whereas interest and principal payments are paid on mortgages.
b. mortgages are provided to households or​ firms, whereas​ mortgage-backed securities are provided mainly to financial institutions.
c. mortgages are​ loans, whereas​ mortgage-backed securities are​ bond-like debt instruments.
d. mortgages are usually used to create a​ portfolio, whereas​ mortgage-backed securities are held separately?