Concept:Each angel in Islam has a specific duty assigned by Allah.Explanation:The angel Mika'il is responsible for bringing rain and distributing sustenance.He waters the earth so that plants grow and food becomes available for all creatures.Mika'il is known as the Angel of Mercy who asks Allah to forgive people's sins.He is also described as a friend to humanity and a guardian of places of worship.Therefore, the angel in charge of rain and the distribution of substances is Mika'il.Answer:B. Mika'il