All of the following are appropriate practices to manage oxidation sources in the operating room EXCEPT: A. administer the lowest concentration of oxygen needed to maintain adequate oxygen saturation B. use a laryngeal mask or endotracheal tube if the patient needs more than 30% supplemental oxygen C. ensure that there are no leaks in the anesthesia circuit D. turn the warmer blower off when using a warming blanket with an attached head drape E. prevent oxygen from accumulating under drapes