Concept:The year 610 C.E. marks the beginning of Muhammad’s (S.A.W) prophethood through the first revelation.Explanation:In 610 C.E., while meditating in the cave of Hira, Muhammad (S.A.W) received the first revelation from Allah through Angel Jibreel.This event is universally recognized as the start of Islam.Therefore, option A is the correct choice.Answer:A. Received the first revelation.