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
The prognosis of rhabdomyosarcoma is likely to be poor if the site of the tumour is: 
Select and explain. 
A. Orbit, B. Extremity, C. Para testicular, D. Urinary bladder
B: Extremity
Answer: B: Extremity 
Explanation: The prognosis of rhabdomyosarcoma is likely to be poor if it involves the extremity. Extremity rhabdomyosarcomas in adolescents and young adults usually have alveolar histologic characteristics and carry a worse prognosis. Other poor prognostic factors associated with it includes age less than 1 and more than 10 years, alveolar histology, unorable primary size, size greater than 5cm and higher clinical group. Ref: CURRENT Diagnosis and Treatment: Surgery, 13th Edition, Chapter 43; Radiation Oncology: Management Decisions By K. S. Clifford Chao, 3rd Edition, Page 755; Kelley's Essentials of Internal Medicine By H. David Humes, 2nd Edition, Page 445.