This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Equilibrium potential of calcium is 
Select and explain. 
A. -32mV, B. +65mV, C. -95mV, D. +130mV
D: +130mV
Answer: D: +130mV 
Explanation: Applying the Nernst equation to external and internal calcium concentrations of 2.5 mM and 0.0001 mM, respectively, results in an equilibrium potential of +134 mV as shown below. (Ref: www.cvphysiology.com)