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
Potential generated due to movement of freely diffusible ions across a semi-permeable membrane is calculated using: 
Select and explain. 
A. Nemst equation, B. Gibbs equation, C. Goldman-Hodgkin-Katz equation, D. Fick principle
A: Nemst equation
Answer: A: Nemst equation 
Explanation: Ans: A. Nemst equation(Ref Ganong 25/e9, p24/e Guyton 13ze p61).Nernst equation:Calculates potential generated due to movement of freely diffusible ions across a semi-permeable membrane.Describes "relation of diffusion potential to ion concentration difference across a membrane".