Which type of therapy is most cost-effective?

Methadone and buprenorphine maintenance therapy is the most commonly used therapy, according to the study. Needle-syringe exchange programs were the second most cost-effective options, followed by test-and treat programs.

Explanation:

producers: apple trees, potatoes, carrots, grains, acorns, cabbage, grass, corn, lettuce

consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls