Concept:The title “al-Amin” means “the trustworthy one.”Explanation:Before his prophethood, Muhammad (SAW) was known among the Quraysh for his honesty and reliability.Because of his consistent truthfulness and trustworthiness, the people of Makkah gave him the title “al-Amin.”Al-Amin directly translates to “the trustworthy.”Answer:C. trustworthy