(a) protection of animals at the highest trophic level

(b) protection of only consumers

(c) protection of only herbivores

(d) comprehensive programme to protect all the physical and biological components

Correct option – ( d )

Explanation – if only one level or one thing will conserved then there will be no significant changes in conservation will be seen . To conserve forests the living organisms and the non living substances both should be conserved . Conservation of both biotic and abiotic community is necessary .