An analyst calculates a gross profit margin of 40 percent based on current year sales of $50 million. She forecasts sales growth of 8 percent and a decline in the gross profit margin from 40 percent to 37 percent. Which of the following statements most likely represents the cause for the decline in the gross profit margin? a. A decrease in cost of sales of $4 million. b. An increase in nonoperating expenses of $4 million. c. An equivalent dollar increase in sales and cost of sales. d. A reduction in the forecasted gross profit relative to the current year