This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen & Pelvis, Subject name: Anatomy
Choose the appropriate lettered structure in this CT scan of the abdomen at the level of the upper lumbar vertebra. Which structure receives bile, concentrates it by absorbing water and salt, and stores it? 
Select and explain. 
A. A, B. B, C. C, D. D
A: A
Answer: A: A 
Explanation: (a) The gallbladder receives bile, concentrates it by absorbing water and salt, and stores it.