1. Liquidity trap is a situation in which:
   1. people want to hold only cash because prices are falling every day
   2. people want to hold only cash because there is too much of liquidity in the economy
   3. the rate of interest is so low that no one wants to hold interest bearing assets and people wants to hold cash
   4. there is an excess of foreign exchange reserves in the economy leading to excess of money supply

The tax whose share in overall taxation revenue has gone up rapidly during the planning period is: