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: Medicine
a' wave in ,JVP is seen in - 
Select and explain. 
A. Will be large when atria contracts against resistance, B. Filling of ventricles, C. It is followed by "V" waves, D. ↓in inspiration
A: Will be large when atria contracts against resistance
Answer: A: Will be large when atria contracts against resistance 
Explanation: None