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
The plateau phase of Myocardial action potential is due to: 
Select and explain. 
A. Eflux of Na+, B. Influx of Ca++, C. Influx of K+, D. Closure of voltage gated K+ channels
B: Influx of Ca++
Answer: B: Influx of Ca++ 
Explanation: Influx of Ca++