A company had an inventory turnover ratio of $6\mathrm{.}2$ in year $1$ and an inventory turnover ratio of $4\mathrm{.}5$ in year $2.$ Which of the following might explain the decrease in the ratio? a$.)$ the percentage increase in average inventory exceeds the percentage increase in cost of goods sold b$.)$ the percentage decrease in average inventory was greater than the percentage decrease in cost of goods sold c$.)$ the percentage increase in cost of goods sold was greater than the percentage increase in average inventory d$.)$ the percentage decrease in average inventory is equal to the percentage decrease in cost of goods sold