During the year ended Dec. 31, 2021; Stanley Inc. had Sales of $12,160.4 million, Cost of merchandise sold of $8,640.9 million, selling, general and administrative expenses of $2,576 million and income tax expense of $258.6 million. Compute Stanley's gross profit margin. Select one: a. 7.8% O b. 10.1% O c None of these are correct. O d. 28.9% O e. 38.0%