You are called to assess a man who has collapsed in the clinic waiting room. A staff nurse has already bleeped the cardiac arrest team.. Start chest compressions at a ratio of 30:2

You are called to assess a man who has collapsed in the clinic waiting room. A staff nurse has already bleeped the cardiac arrest team. On arrival the man is laid on his back. You open the airway with a head-tilt chin lift - after assessing for 10 seconds there are no signs of breathing. What is the most appropriate next step?
A.A Start chest compressions at a ratio of 15:2
B.A Place in the recovery position
C.A Check for a carotid pulse for 10 seconds
D.A Give 2 rescue breaths
E.A Start chest compressions at a ratio of 30:2***