Which of the following statements about defibrillation is true? - it is an electrical shock that may help the heart to resume an effective rhythm to a person in sudden cardiac arrest
- it’s not a link in the cardiac chain of survival
- it’s more likely to be successful if CPR is withheld
- it’s commonly used on a person complaining of chest pain

Immunization is the introduction of a foreign substance to provoke  the immune response system.  immunizations are the same as vaccinations. it introduces foreign (but dead/ weakened) illnesses to train the body to fight against them. specific viruses and bacteria have specific antigens, antigens act sort of like name tags. these name tags the immune system recognize what's dangerous to the body and what's safe.