For Adults/Adolescents, you should call/activate EMS: Before providing CPR. After providing CPR for 2 minutes. After an AED has been administered. Or, none of the above.

Before providing CPR is the correct option.

Explanation:

CPR refers to the cardiopulmonary resuscitation in which the user follows the emergency treatment of respiration from mouth to mouth and chest compression. If any person complete training of Adults/Adolescents then they have to activate or call the EMS before providing cardiopulmonary resuscitation.