A liquidity trap is a situation in which: a. using expansionary monetary policy is not effective because, the nominal interest rate is almost zero.
b. lenders are trapped by large loans with declining rates of return. using expansionary monetary policy is not effective, because the real interest rate is negative.
c. aggregate demand falls, because consumers do not have enough liquidity to consume.
d. using expansionary fiscal policy is not effective because, the budget is in a deficit.