12. Mortgage rates have been increasingly sharp in the US recently, due in part to actions of the Federal Reserve. What are the policy actions of the Fed or the US Treasury that have led to such sharp increases in interest rates?

a. An increase and required Reserve ratio

b. an increase in 30 year treasury bond yields engineered by the Fed

c. increase printing of money by the FED to pay for various programs

d. an increase in discount rates which affect the inter-bank borrowing rate known as federal funds rate

e. none of the above