Choice "B" is correct.

The computation derives purchases using the BASE mnemonic where B is the beginning inventory computed at 40% of January's production requirements and E is the ending inventory at 40% of February's production requirements. Both are multiplied by the 4 pounds of raw material needed. Amounts subtracted from inventory, the "S", are the items produced in January, multiplied by the 4 pounds of raw materials needed. We then squeeze the purchases from the formula: ending inventory of 17,600 + 48,000 units produced - beginning inventory of 19,200, which equals 46,400.

Choice "a" is incorrect. It does not consider the raw material conversion of 4 pounds per unit.
Choice "d" is incorrect. This response simply considers the amount of units sold converted to raw materials.Choice "c" is incorrect. This response is the sum of the units sold in February and the ending inventory requirements.