Which of these economic problems is the MOST DIFFICULT to solve? a. Unemployment
b. Scarcity
c. Shortages
d. Inflation

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.

a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )

answer; internal; covert processes;