The following production data were taken from the records of the Finishing Department for June:

$\backslash$table$[[$Inventory in process, June $1(35\%$ completed$),5,000$ units$],[$Completed units during June,$57,800$ units$],[$Ending inventory $(61\%$ complete$),2,700$ units$]]$

The number of materials equivalent units of production in the June $30$ Finishing Department inventory, assuming that the first$-$in$,$ first$-$out method is used to cost inventories and materials were added at the beginning of the process, is

$$ a$.52,800$ units

$$ b$.60,500$ units

c$.2,700$ units

d$.55,500$ units