4. In the given food chain, suppose the amount of energy at the fourth trophic level is 5 kJ, what will be the energy available at the producer level?

Grass → Grasshopper → Frog → Snake → Hawk

(a) 5 k J

(b) 50 k J

(c) 500 k J

(d) 5000 k J

Correct option – ( d )

Explanation for correct option – at a particular trophic level the available energy level is 10 times the energy level at next trophic level . At fourth level energy ids 5 kJ , so at third level it would have been 50 KJ .Similarly at second level 500 kJ and at the first level 5000 KJ . 

Explanation for incorrect option – 5 KJ at fourth level

                                                              50 KJ at third level

                                                              500 KJ at second level

Hence correct option is 5000 kJ