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
Hemoglobin is present in: 
Select and explain. 
A. Hydrophilic pockets, B. Hydrophobic pockets, C. Pyrrole rings, D. Cationic ring
B: Hydrophobic pockets
Answer: B: Hydrophobic pockets 
Explanation: Hydrophobic pockets