Many small rural communities
a. do not have mass transit systems
c. are small enough to walk everywhere
b. have the best mass transit systems
d. all of the above

answer; i believe that the correct answer to the above question is; (tariff)

d is the correct answer.

b is incorrect because it makes food by itself

c is incorrect because us humans don't know how to produce their own food using the sun like plants.

a is incorrect because consumers can depend on carnivores for eating food for consumers to eat the dead organism. same thing with omnivores.