Answer:
The answer is:
when a nation's central bank makes an open market purchase of 20-year bonds, short-run effect is that the quantity of money in circulation increases, interest rates are low because the nation's commercial banks have more money to lend. Households and businesses are motivated to borrow money because of low rates
Step-by-step explanation:
This is a monetary tool - open-market operation which is a situation in which when the central bank purchases securities inorder to increase the money supply and sells securities to decrease the money supply.
So when a nation's central bank makes an open market purchase of 20-year bonds, short-run effect is that the quantity of money in circulation increases, interest rates are low because the nation's commercial banks have more money to lend. Households and businesses are motivated to borrow money because of low rates.
This is usually done to stimulate the economy i.e to stop the economy from slowing down.