The nurse determines clinical death and initiates CPR immediately. How long is resuscitation considered possible?
a. If cardiopulmonary arrest has existed for no more than 2 minutes
b. If cardiopulmonary arrest has existed for no more than 3 minutes
c. If cardiopulmonary arrest has existed for no more than 4 minutes
d. If cardiopulmonary arrest has existed for no more than 5 minutes