Non-Alaskan grizzly bears are indicator species for mountain ecosystems. In the nineteenth century, the grizzly bear nearly went

extinct in the lower forty-eight states and were eventually added to the federal Endangered Species List as a threatened species in

1975. Ranching and farming have driven the grizzly from the open plains, and today the species lives mostly in mountains and

forests. The reason for including the grizzly in the list of animal indicator species is that

Explanation:

Animal indicator list is a barometer to check how a particular ecosystem is affecting the lives of particular animals. The indicator measures  stress or behavior in the ecosystem to know whether to protect  the specie or allow them undisturbed

This is to avoid or reduce to barest minimum incidences of extinction of such specie in the ecosystem.

The grizzly sudden reduction in number from well over 100,000 in California to less than nothing in 1942 triggered  the need to protect the grizzlies from human destruction and possible extinction. Grizzlies was a national specie and appeared in the flag of California. The population gradually reduced in most of the states of Idaho, Utah, Alaska and many more.

The grizzlies in 1975 were declared protected species to avoid being hunted or trapped by humans and to repopulate them in the areas where they once lived. Their future will depend largely on humans ability to allow them to coexist with them, by setting out a large area for them to live and regroup.

This will go to balance the ecosystem which has been tampered or disturbed by development.

the answer is b. apsidal precession