The fiscal 2021 financial statements for Walgreens Boots Alliance, Inc., report net sales of $164,370 million, net operating profit after tax of $4,687 million, net operating assets of $39,502 million. The 2020 balance sheet reports net operating assets of $42,683 million. Walgreen's 2021 net operating asset turnover is: (round up to the nearest) Select one: O a.4.0 b. 6,0 O c.4.2 O d. 25%