This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Growth and development, Subject name: Pediatrics
[{'content': 'A child&;s growth variation is normal but bone development is not according to the chronological age. What is diagnosis? \nSelect and explain. \nA. Genetic, B. Dwarfism, C. Constitutional delay, D. Familial sho stature', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In constitutional delay, the bone age corresponds to the child&;s height age but is lower than chronological age by 2-4 yrs . Skeletal age is usually assessed by radiographic study of left hand and wrist. Ref- OP.Ghai, 9th edition', 'role': 'assistant'}]