Past experience has shown that the ending inventory for each month should be equal to 10% of the next month's sales in units. The inventory on May 31 fell short of this goal since it contained only 400 units. The company needs to prepare a Production Budget for the next five months.

The beginning inventory in units for September should be:

A) 460 units

B) 6,800 units

C) 540 units

D) 680 units