The correct answer is B.  

Your first action should be to check if the victim is unresponsive.  If the victim is an unresponsive adult, you should activate the hospital emergency response system.  If emergency equipment (including an AED) is available, you should get it at the same time you activate the emergency response system.  

Answer a is incorrect because after you activate the emergency response system, you should return to the collapsed victim and perform CPR until the emergency response team arrives.  

Answer c is incorrect because you should not place the victim in the recovery position until you have determined that he is breathing normally and has signs of circulation.  You have performed no assessment on this victim that would justify placing him in the recovery position - the victim could be in cardiac or respiratory arrest.  

Answer d is incorrect because you should not provide mouth-to-mouth breathing before you determine that the victim is unresponsive, open the airway, and check for breathing.  After you confirm that the victim is unresponsive, you should be sure that you or someone else has activated the emergency response system.