If the central bank unexpectedly shifts to a more restrictive monetary policy, the most likely effect（）

单项选择题If the money interest rate is measured on the y-axis and the quantity of money is measured on the x-axis, the money supply curve is:（）

A. horizontal.
B. upward sloping to the upper right.
C. vertical.

单项选择题Which of the following are four phases of the typical business cycle（）

A. Peak, boom, bust, and recession.
B. Peak, expansion, recession, and stability.
C. Peak, contraction, recessionary trough, and expansion.