Which of the following is the proper rate and depth for adult chest compressions?

• A. 60 compressions per min; 3 inches in depth
• B. 120 compressions per min; 3 inches in depth
• C. 100 compressions per min; 2 inches in depth
• D. 100 compressions per min; 3 inches in depth

Answer: (C)

Effective CPR relies on delivering chest compressions at a pace and depth that maximize blood flow to vital organs. For adults, aim for about 100 to 120 compressions per minute and a depth of at least 2 inches (about 5 cm), with full chest recoil between compressions. The option with 100 compressions per minute and 2 inches depth aligns with these guidelines, providing sufficient perfusion without over-compressing the chest. The other choices either use too slow a rate, compress too deeply, or both—for example, 3 inches can exceed the recommended maximum depth and increase injury risk, and 60 per minute is too slow to maintain adequate perfusion.