When Banks Make Rules on Maximum Permissible Mortgage Payments for Borrowers,they

When banks make rules on maximum permissible mortgage payments for borrowers,they use:

A) nominal interest rates,and economists feel that this practice is appropriate.
B) real interest rates,and economists feel that this practice is appropriate.
C) real interest rates,but economists feel that this practice is inappropriate.
D) nominal interest rates,but economists feel that this practice is inappropriate.