Calla sees her 10 year old sister choking. She does the five-and-five approach. What did Calla do? O She did five chest compressions and then five rescue breaths.
She did five rescue breaths and then five chest compressions.
O She did five blows on the back and then five abdominal thrusts.
She did five abdominal thrusts and then five blows on the back.

What Calla did was give her sister five blows on the back and then five abdominal thrusts.

Explanation:

Five-and-five approach is a first aid technique used in first aid in case of choking. This procedure consists of:

Choking occurs when food or an object blocks the airway and prevents normal breathing.  In the case of Calla, she performed the five-and-five approach to try to help her sister breathe.

The other options do not correspond to the correct technique because:

    - Alternating breaths with chest compressions is used when cardiorespiratory arrest exists.

    - Five-and-five approach consists in giving first the blows in the back and then abdominal thrusts.

relationship between pressure and air volume and led to the understanding of how respiration works; i believe this is the correct answer ; /// good luck