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
Example of active transpo ? 
Select and explain. 
A. Movement of water across cell membrane, B. Movement of oxygen across cell membrane, C. Cotranspo of amino-acids with Na+, D. None of the above
C: Cotranspo of amino-acids with Na+
Answer: C: Cotranspo of amino-acids with Na+ 
Explanation: Ans. is 'c' i.e., Cotranspo of amino-acids with Na+