Heat integration is planned in a process plant at an investment Rs. 2x10$^{6}$. This would result in a net energy savings of 20 GJ per year. If the nominal rate of interest is 15% and the plant life is 3years, then the breakeven cost of energy, in Rs. per GJ (adjusted to the nearest hundred), is

1. 33500
2. 43800
3. 54200
4. 65400