Solution:(b) The decision to change the hospital saved the life of the daughter of the doctor. (Correct)(a) The decision to change_a_hospital saved an life of the daughter of the doctor. (Incorrect Article)
(c) The decision to change an hospital saved the life of the daughter of the doctor. (Incorrect Article)
(d) A decision to change a hospital saved the life of the daughter of the doctor. (Incorrect Article)