This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardio thoracic surgery  , Subject name: Surgery
Thoracic outlet syndrome is seen most commonly in which age group 
Select and explain. 
A. Children, B. Elderly, C. Middle aged women, D. Atheletes
C: Middle aged women
Answer: C: Middle aged women 
Explanation: .THORACIC OUTLET SYNDROME (TOS) It is syndrome complex due to neurovascular bundle compression in the thoracic outlet. Thoracic outlet has got two main spaces: * Scalene triangle is bound by scalenus anterior, scalenus medius and first rib. It contains subclan aery and brachial plexus. * Costoclavicular space is bound by clavicle, first rib, costoclavicular ligament and scalenus medius. It contains subclan aery and vein and brachial plexus. Causes - * Cervical rib. * Long C7 transverse process. * Anomalous inseion of scalene muscles. * Scalene muscle hyperophy. * Scalene minimus. * Abnormal bands and ligaments. * Fracture clavicle or first rib. * Exostosis. * Tumours in the region. * Brachial plexus trauma and diseases. ref:SRB&;s manual of surgery,ed 3,pg no 378