Which one of the following statements best reflects the critical message conveyed by the passage given above ?

Correct Option: (d) Antibiotics should only be used to treat diseases.

The passage discusses how antibiotics are fed to livestock as growth promoters, leading to superbugs and multi-drug resistant pathogens that can affect humans. It notes that some farming companies and countries like Denmark banned antibiotic growth promoters, resulting in healthier animals and better production. The critical message conveyed is addressing the root cause of this resistance by restricting the unnecessary use of antibiotics (specifically as growth promoters) to treating diseases. Option (d) ('Antibiotics should only be used to treat diseases') directly captures this pragmatic policy takeaway. Option (a) and (b) advocate extreme shifts away from animal farming or consumption, which is not supported. Option (c) is too broad as it bans all antibiotic use on animals, whereas therapeutic use is necessary; the ban is specifically on growth-promoting antibiotics. Thus, option (d) is correct.