This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
According to American College of Rheumatology, all of the following are clinical criteria for the diagnosis of osteoahritis, EXCEPT: 
Select and explain. 
A. Lack of warmth, B. Atrophy of quadriceps muscles, C. Crepitus, D. Age > 50 years
B: Atrophy of quadriceps muscles
Answer: B: Atrophy of quadriceps muscles 
Explanation: Clinical criteria for the diagnosis of osteoahritis, established by the American College of Rheumatology, include: Age > 50 years Stiffness < 30 minutes Crepitus Bony tenderness Bony enlargement Lack of warmth The presence of 3 of these 6 criteria in the patient with chronic knee pain is 95% sensitive and 69% specific for the diagnosis of osteoahritis. Ref: Gross A., Ma C.B. (2013). Chapter 12. Approach to the Patient with Knee Pain. In J.B. Imboden, D.B. Hellmann, J.H. Stone (Eds), CURRENT Diagnosis & Treatment: Rheumatology, 3e.