Passage Summary: A doctor thinks a patient's pain came from a pinched nerve. Since a shot that reduces swelling fixed the pain, the doctor concludes the pinched nerve was definitely the culprit.

Conclusion: Pressure on the nerve was the cause of the patient's back and leg pain.

Reasoning: Nerve pressure causes inflammation, which causes pain, and a treatment specifically for inflammation successfully relieved the patient's pain.

Analysis: The doctor is assuming a clean causal chain: Pressure leads to Inflammation, which leads to Pain. The treatment fixed the inflammation, which fixed the pain. However, the argument has a gap: it assumes the cortisone didn't fix the pain through some other mechanism, or that the inflammation wasn't caused by something else entirely. Look for an answer that the doctor *needs* to be true, such as the idea that the inflammation was actually caused by the pressure and not some unrelated factor.