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
True regarding cardio pulmonary resuscitation is 
Select and explain. 
A. Most conunon presentation in ECG is asystole, B. Compression to ventilation ratio is 5:1, C. Adrenaline is given if cardioversion fails., D. Calcuim gluconate is given immediately.
C: Adrenaline is given if cardioversion fails.
Answer: C: Adrenaline is given if cardioversion fails. 
Explanation: None