Passage Summary: Nutritionists say five fruits or veggies a day gives you all your vitamins, but since most people don't eat that many, the author concludes they must take supplements instead.

Conclusion: Most people need to take vitamin pills to meet their daily requirements.

Reasoning: Five servings of produce provide enough vitamins, but most people don't eat that much produce.

Analysis: The author assumes that if you don't get vitamins from five servings of produce, you must get them from pills. To weaken this, we need to find another way people might be getting their vitamins. Look for an answer that suggests people get vitamins from other sources, like fortified foods (cereal, milk) or smaller amounts of very nutrient-dense foods that aren't necessarily 'five servings.' The argument fails to account for the variety of the modern diet.