Solution
✅ Correct Option: 4
The passage first introduces the growing problem of knee injuries, then explains causes and consequences, and finally gives preventive and treatment-related measures. That is a problem-solution structure covering causes, effects and prevention. Option 1 is wrong because there is no chronological history of medical interventions. Option 2 is wrong because the passage does not compare surgical and non-surgical rehabilitation. Option 3 is wrong because it does not mainly argue for institutional regulation of fitness practices. Option 4 is right because it accurately describes the way the passage moves from the problem to causes and preventive strategies.