Police Officers at the Scene of a Fire

Police officers at the scene of a fire:

A) Do not need a warrant to remain in a burned building to look for injured victims,do not need a warrant to remain in a burned building to investigate the cause of the fire or explosion,must get a warrant to search for evidence of crime once they determine the cause of the fire,and can search suspicious onlookers without a warrant.
B) Do not need a warrant to remain in a burned building to look for injured victims,do not need a warrant to remain in a burned building to investigate the cause of the fire or explosion,but must get a warrant to search for evidence of crime once they determine the cause of the fire.
C) Can search suspicious onlookers without a warrant.
D) Do not need a warrant to search for evidence of a crime even after the cause of the fire is determined.