An adult casualty isn't breathing. To maintain circulation, CPR should be given. What's the correct depth to press down on their chest? An adult casualty isn't breathing. To maintain circulation, CPR should be given. What's the correct depth to press down on their chest?

• Possible answers:

   
• A. 1 to 2 centimetres
• B. 5 to 6 centimetres
• C. 10 to 15 centimetres
• D. 15 to 20 centimetres