What would most likely happen to the food web if the amount of grass drastically decreased? the mouse and grasshopper would be affected. only the rabbit would be affected. the grasshopper, mouse, and shrew would be affected. the entire food web would be affected.

The correct answers is option D, The entire food web would be affected.

Explanation:

A food web is just like an airplane, even if a single bolt is removed or disturbed in it, the entire plane functioning get disturbed.  

Thus , if the amount of grass decreases drastically, all the species that depends on grass as a primary source of food get disturbed and thus their population will reduce due to lack of availability of food. Therefore all other species which depend on the species depending on grass will also get affected and like wise the impact of grass reduction will affect all the components of food web.