You're shopping for a mortgage loan which is available from: a) a bank at a nominal annual rate of 13% compounded semi-annually. b) a credit union at...

You're shopping for a mortgage loan which is available from:

a) a bank at a nominal annual rate of 13% compounded semi-annually.

b) a credit union at 12.50% nominal annual rate compounded monthly

c) a loan company at 12.75% nominal annual rate compounded quarterly.

which is the lowest-cost loan, given all other terms are the same? If needed, you can assume any payment frequency.