Critical Reasoning (CR) | A 24-year study of 1,500 adults showed that those subjects

A 24-year study of 1,500 adults showed that those subjects with a high intake of foods rich in beta- carotene were much less likely to die from cancer or heart disease than were those with a low intake of such foods. On the other hand, taking beta-carotene supplements for 12 years had no positive or negative effect on the health of subjects in a separate study of 20,000 adults.

Each of the following, if true, would help to resolve the apparent discrepancy between the results of the two studies
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