What is Neighborhood?

Hi is anyone here?

Sat no calculator section question in the picture

The authors use the word “backbone” in lines 3 and 39 to indicate that

These three organisms are interdependent on each other for their survival. what will happen if foxes are eliminated from the region? a. there will be more rabbits and less grass in the region. b. there will be more grass and fewer rabbits in the region. c. there will be fewer rabbits and less grass in the region. d. there will be more rabbits and more grass in the region.