Topaz Company sold and produced 40,000 units of product at a cost of \($1,200,000\) for a sales price of \($60\) per unit during the most recent year. Throughout the year its average inventory was 4,000 units with an average cost of \($120,000\). Based on this information, which of the following cannot be determined about Topaz’s inventory management performance?

a. Topaz’s inventory turnover in units was 10 times.

b. Topaz’s gross margin return on average inventory investment was 1|,000%.

c. Topaz’s inventory turnover in dollars was 10 times.

d. Topaz’s production cycle efficiency was 100%.