-Based on Common Size Analysis, Which of the Following Statements

$\begin{array}{l}\text { Consider the following statement of earnings data for Mandrake Mills Inc. }\\\begin{array} { | l | r | r | } \hline & \mathbf { 2 0X7 } & \mathbf { 2 0 X 6 } \\\hline \text { Sales revenue } & \$ 97,300 & \$ 86,200 \\\hline \text { Less: Cost of goods sold } & \underline { 45,600 } & \underline { 53,400 } \\\hline \text { Gross profit } & 51,700 & 32,800 \\\hline \text { Selling and administration expense } & \underline { 22,500 } & \underline { 18,300 } \\\hline \text { Income before income tax } & \$ 29,200 & \$ 14,500 \\\hline\end{array}\end{array}$
-Based on common size analysis, which of the following statements is correct

A) the increase in sales revenue in 20X7 was caused by higher selling and administrative expenses.
B) the increase in gross pro?t in 20X7 was due to increased sales.
C) income before income tax as a percent of sales declined in 20X1.
D) the company's cost to sales ratio improved in 20X7.