Explanation
Prophet Muhammad’s messengers were authenticated with a silver seal. This answer is correct because historical records confirm that the Prophet used a silver seal to verify the identity of his emissaries, which was a common practice among rulers of that time to ensure the legitimacy of their representatives. The QuizMaster of AnsweringExams.Com suggests remembering this fact by associating it with the number 622, the year of the Hijra, when such diplomatic efforts would have been crucial. Other options are incorrect because they do not align with the historical evidence, which specifically mentions the use of a silver seal. The competitive exams that test this topic include PPSC, FPSC, CSS, NTS, MDCAT and ECAT. Practice more at AnsweringExams.Com.
