Foremost Corporation Manufactures Boxes Finished Goods Inventory at the End of December Was 900

Foremost Corporation manufactures boxes. The estimated number of boxes sold for the first three months of the current year are: $$\begin{array} { l l } \text { Month } & \text { Sales } \\\text { January } & 3,000 \\\text { February } & 4,200 \\\text { March } & 3,900\end{array}$$ Finished goods inventory at the end of December was 900 units. Ending finished goods inventory is equal to 20 percent of the next month's sales. General Corporation expects to sell the boxes for $5 each. April sales is projected at 4,500 boxes. What is the expected sales revenue for March?

A) $15,000
B) $21,000
C) $19,500
D) $4,500