Passage Summary: Most vegetarians are healthy at 50, so the author assumes that not eating meat is what made them healthy and tells everyone else to quit meat too.

Conclusion: People should avoid meat to lower their risk of heart disease.

Reasoning: A high percentage (75%) of vegetarians reach age 50 without heart disease, which supposedly proves that vegetarianism causes better heart health.

Analysis: This argument suffers from a classic correlation-to-causation error. Just because 75% of vegetarians are healthy doesn't mean the diet caused the health; perhaps vegetarians also exercise more or smoke less. Furthermore, we don't know the percentage for meat-eaters—if 90% of meat-eaters are healthy, then vegetarianism actually looks bad! The structure is: 'Most X have property Y, so doing X causes Y, therefore do X.' Look for an answer that uses a high percentage within a specific group to claim a causal benefit without providing a comparison group.