The Hemoglobin Disocciation Curve After return of circulation

You are second year medical student and you have chance to volunteer as life guard in Hawaii. As you enjoy your time in there, you'll happen to see elderly, little obese gentleman to collapse in beach. Immediately you run to this gentleman and test for breathing and pulse. You manage to feel breathing and you get pulse from the carotid arteries. HR is about 60. When ambulance come to the scene you connect gentleman to the monitor. Almost immediately you see that patient went from sinusrhythm to asystole. You start cardiopulmonary resuscitation (CPR) and after 25 minutes you get return of spontaneous circulation (ROSC). If you could draw blood from the patient and analyse the dissociation curve of patients hemoglobin, you would propably see (compared to patients normal condition):

a) dissociation curve to move left
b) no changes
c) dissociation curve to move right
d) you wouldn't have any hemoglobin from patients RBCs