Elston Company Compiled the Following Financial Information as of December

Elston Company compiled the following financial information as of December 31, 2017: $$\begin{array} { l r } \text { Service revenue } & \$ 840,000 \\\text { Common stock } & 180,000 \\\text { Equipment } & 240,000 \\\text { Operating expenses } & 750,000 \\\text { Cash } & 210,000 \\\text { Dividends } & 60,000 \\\text { Supplies } & 30,000 \\\text { Accounts payable } & 120,000 \\\text { Accounts receivable } & 90,000 \\\text { Retained earnings, } 1 / 1 / 17 & 450,000\end{array}$$ Elston's retained earnings on December 31, 2017 are

A) $450,000.
B) $540,000.
C) $480,000.
D) $ 30,000.