Zeechan Landscaping Company Limited Had Sales Revenues of $1,400,000 Last

Zeechan Landscaping Company Limited had sales revenues of $1,400,000 last year and $1,200,000 the year before. Cost of Goods Sold was $980,000 last year and $780,000 the year before. Operating expenses were $300,000 for both last year and the year before. Comparing gross profit and operating profit margins, it could be concluded that

A) The operating profit margin remained unchanged over the previous two years as increases in cost of goods sold, CGOS, were offset by improvements in operating expenses
B) The operating margin remained unchanged over the previous two years as cost of goods sold increases were approximately proportional to gains in sales revenue
C) The operating margin declined last year over the year before due to increases in costs per unit sold.
D) The operating margin declined last year over the year before as operating expenses did not respond to economies of scale
E) The gross profit margin of the operating profit margin were unchanged resulting in no change in earnings before interest and taxes