The best description of the purpose of "hands-only" CPR is: Hands-only CPR was designed for those who are not trained or feel uncomfortable delivering mouth-to-mouth breaths. It doesn't replace traditional CPR.
This option highlights that hands-only CPR is a simplified method intended for bystanders who may not have formal training or may be hesitant to provide rescue breaths, while still allowing them to effectively assist someone in cardiac arrest. It does not fully replace traditional CPR, which includes both chest compressions and rescue breaths.