What is the compression depth for a child during CPR?

The correct compression depth for a child during CPR is indeed one-third of the chest depth. This guideline is based on the anatomical differences between children and adults, recognizing that children have smaller bodies and shallower chests. This depth ensures that compressions are effective in delivering adequate blood flow during cardiac arrest, optimizing the chances of favorable outcomes.

This measurement is crucial because compressions at this depth allow for sufficient recoil of the chest, which helps to maintain blood flow to vital organs, particularly the heart and brain. Compressions that are too shallow may not generate enough pressure to circulate blood effectively, while deeper compressions may risk injury to the child's delicate structures.

Option descriptions that deviate from this standard would not adequately meet the physiological requirements for performing CPR on a child, hence they are not the best practice.