Passage Summary: If companies stop making cheap penicillin, doctors will be forced to use powerful new drugs for minor issues, which will eventually lead to the rise of superbugs.

Conclusion: The shift toward using newer, more powerful antibiotics is likely to cause an outbreak of drug-resistant bacteria.

Reasoning: Profit motives may lead to a shortage of penicillin, forcing doctors to use broad-spectrum antibiotics even when they are not strictly necessary.

Analysis: To complete this argument, we need to provide the biological 'why' that connects the unnecessary use of powerful drugs to the creation of resistant bacteria. The stimulus sets up a scenario of over-prescription; the missing piece is the fact that overusing these broad-spectrum drugs is exactly what allows bacteria to evolve resistance. Look for an answer that explains how the frequent or unnecessary use of these specific antibiotics facilitates the development of drug-resistant strains.