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
Which of these hormones activate catalytic receptors? 
Select and explain. 
A. GH, B. IGF1, C. Leptin, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Catalytic receptors are those receptors that directly act as enzymes when the hormone binds to them. E.g. tyrosine kinase receptors Hormones That Use Receptor Tyrosine Kinase Signaling Growth hormone Insulin Leptin Prolactin Growth factors