Passage Summary: A doctor notices that a certain protein usually goes up when blood pressure goes up. Since Disease X raises that protein, the doctor concludes the disease must be causing high blood pressure.

Conclusion: Disease X is a cause of high blood pressure.

Reasoning: Angiotensinogen levels are positively correlated with blood pressure, and Disease X typically increases those protein levels.

Analysis: The doctor is making a classic leap from correlation to causation. Just because two things—protein levels and blood pressure—tend to move together doesn't mean one causes the other, nor does it mean that something affecting the protein (Disease X) will necessarily cause the blood pressure to spike. We should look for an answer choice that points out this logical gap, specifically that the protein might just be a byproduct or a middleman rather than the actual cause of the high blood pressure.