Consider the following statements concerning food chains.
I. Removal of 80% tigers from an area resulted in greatly increased growth of vegetation
II. Removal of most of the carnivores resulted in an increased population of deers
III. The length of food chains is generally limited to 3-4 trophic levels due to energy loss
IV. The length of food chains may vary from 2 to 8 trophic levels
Which of the two above statements are correct?
(a) I and II
(b) ll and lll
(c) III and IV
(d) I and IV