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Set 1: Inferences (Intermediate)

Explanation

Answer: B

PASSAGE

Recent studies of the microbiome—the trillions of bacteria living in the human gut—suggest that these organisms influence not only digestion but also mood, immunity, and cognitive function. Scientists now refer to the gut as 'the second brain,' though the mechanisms connecting gut bacteria to mental health remain only partially understood.

Based on the passage, what can be inferred about scientific understanding of the microbiome?

A. The connection between gut bacteria and mental health has been fully explained.
B. Researchers have identified significant correlations but lack complete explanations.✓ Correct
C. The microbiome only affects digestive processes.
D. Scientists no longer consider gut health important.

Detailed Explanation

The passage states mechanisms 'remain only partially understood'—correlations exist but explanations are incomplete.

Key Evidence:

• "mechanisms remain only partially understood"

• "influence mood, immunity, and cognitive function"

Why others are wrong: A ('Partially understood' contradicts 'fully explained.'), C (It affects mood, immunity, and cognition too.), D (It's called 'the second brain'—clearly important.).

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