This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine System, Subject name: Physiology
True about Laron dwarfism is: 
Select and explain. 
A. Growth hormone deficiency, B. Growth hormone insensitivity, C. Plasma IGF-1 is markedly increased, D. Plasma IGF-BP3 at normal levels
B: Growth hormone insensitivity
Answer: B: Growth hormone insensitivity 
Explanation: Laron dwarfism, Plasma GH is normal or elevated GH receptors are unresponsive as a result of loss-of-function mutations of the gene for the receptors. Resultsin growth hormone insensitivity. Plasma IGF-I is markedly reduced, along with IGFBP 3 (IGF-binding protein-3)