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': 'Flexion of metacarpophalangeal joint and extension of interphalangeal joints is major action of \nSelect and explain. \nA. Palmar interossei, B. Dorsal interossei, C. Lumbricals, D. FDS', 'role': 'user'}, {'content': 'Answer: C \nExplanation: It is the action of lumbricals.The dorsal interossei abduct the fingers. the palmar interossei adduct the fingers.The FDS flexes middle phalanx at PIP joints. ref :textbook of anatomy upper limb and thorax ,vishram singh ,2nd edition ,page no.144', 'role': 'assistant'}]