Case:
Elmer donated a pint of blood that his wife Doris needed during operation. Elmer and Doris were subsequently divorced. Several years after the divorce Elmer was in an accident and needed a pint of blood. His new wife, Cora, was of a different blood type, and thus could not contribute blood to Elmer. Doris still lived in the same area as Elmer, and there were no health-related reasons that would have prevented her from donating blood.

Was Doris morally obligated to donate a pint of blood to Elmer; “Yes,” “No,” or “It depends”? Whatever your response explain the reasoning behind it.