The Molding Department of Kennett Company has the following production data: beginning work in process $25,000$ units $(60\%$ complete$),$ started into production $400,000$ units, completed and transferred out $3750,000$ units, and ending work in process $50,000$ units $(40\%$ complete$).$ Assuming materials are entered at the beginning of the process, equivalent units for materials are:

$425,000.$

$450,000.$

$475,000.$

$375,000$