This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Preoperative assessment and monitoring in anaesthesia, Subject name: Anaesthesia
Lightly anaesthetized patient in the lithotomy position (?spontaneously breathing):which of the following is true? 
Select and explain. 
A. Marked reduction in vital capacity, B. Increased FRC, C. Normal alveolar ventilation, D. Residual volume & closing volume equal
D: Residual volume & closing volume equal
Answer: D: Residual volume & closing volume equal 
Explanation: no change to VC decrease in FRC decreased alveolar ventilation CV approaches FRC