This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
[{'content': 'Which of the following muscle is not in the pectoral region? \nSelect and explain. \nA. Pectoralis major, B. Infraspinatus, C. Pectoralis minor, D. Subclavius', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Muscles of pectoral region:- Pectoralis major , pectoralis minor , subclavius and serratus anterior. Largest muscle of pectoral region- pectorals major. Key muscle- pectoralis minor. Infraspinatus- muscle of scapular region. {Reference: vishram singh, page no.40, chapter 3}', 'role': 'assistant'}]