Concept:Khadijah (RA) was the first wife of Prophet Muhammad (SAW), and her age at marriage is a well-known fact in Islamic history.Explanation:Khadijah (RA) was a respected and wealthy Qurayshi widow.She married Prophet Muhammad (SAW) before he received prophethood.At the time of marriage, the Prophet (SAW) was 25 years old.Khadijah (RA) was approximately 40 years old.Therefore, option A is the correct age.Answer:A. 40