Department $M$ had $2,700$ units $57\%$ completed in process at the beginning of June, $14,000$ units completed during June, and $1,100$ units $27\%$ completed at the end of June. The number of equivalent units of production for conversion costs for June if the first$-$in$,$ first$-$out method is used to cost inventories is

a$.14,297$ units

b$.11,300$ units

c$.15,397$ units

d$.12,758$ units