MAD produces biscuits and uses process costing systems. MAD wants to know the correct procedure of showing the physical flow of production units during a given month under the weighted average method? a. Physical units in beginning work in process + units started units completed and transferred out = units in ending work in process. b. Some other procedure not listed here c. Units in ending work in process + units in beginning work in process = units started + units completed and transferred out. d. Units started + units completed and transferred out + units in ending work in process = units in beginning work in process. e. Units in beginning work in process units started + units completed and transferred out = units in ending work in process.