This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Which of the following is not a peptide/protein 
Select and explain. 
A. Growth hormone, B. Insulin, C. PTH, D. Glucocoicoids
D: Glucocoicoids
Answer: D: Glucocoicoids 
Explanation: Ans. is 'd' i.e., Glucocoicoids