Final answer:
The correct rate of chest compressions for a two-year-old in cardiac arrest is 100 compressions per minute (Option B), meeting the general CPR guidelines for chest compression depth and frequency.
Step-by-step explanation:
The rate of chest compressions for a two-year-old in cardiac arrest is 100 compressions per minute (Option B). This rate is consistent across all ages, including children, and is set to be quick enough to maintain circulation but also allow for full recoil of the chest between compressions. The technique of CPR (Cardiopulmonary Resuscitation) includes chest compressions at least 5 cm deep and at this rate, which coincidentally aligns with the beat of the song "Staying Alive" by the Bee Gees.