Cartels are difficult to maintain because
a. antitrust laws are difficult to enforce.
b. cartel agreements are conducive to monopoly outcomes.
c. there is always a tension between cooperation and self-interest in a cartel.

C

Explanation:

Cartels are difficult to maintain because there is always a tension between cooperation and self-interest in a cartel.

There is always the temptation that selfish tendencies develop amoung cartels and tha ability to cooperate becomes more difficult. Take for example OPEC is the best know example for an international cartel. Presntly Russia and Saudi Arabia are at logerheads over production of oil. Instead of them to stick within the rules of how much oil can be oroduced in a day, because of their selfish interest some of them want to produce more . This becomes difficult to maintain

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.

glass wants to live in a world of super heroes and villains. he have lived all his life trying to be responsible for the creating the origin story of a super hero; he schemed and caused many incidents (many of them fatal) hoping that someday someone with superpowers would show up and save the day.

he knew himself very much. he saw himself as a villain of a real-life super hero story. he was aware of his strengths (more than smart enough for being manipulative and scheming) and weaknesses (having fragile bones and having to rely on his mind to succeed).