The Total Assets and the Total Liabilities of Smart Financial

The total assets and the total liabilities of Smart Financial Services are shown below.The company issued no common stock and paid no dividends during the year. $$\begin{array} { | l | r | r | } \hline & \text { Assets } & \text { Liabilities } \\\hline \text { Beginning of year } & \$ 405,000 & \$ 270,000 \\\hline \text { End of year } & 455,000 & 300,000 \\\hline\end{array}$$ What was the amount of net income for the year?

A) $50,000
B) $30,000
C) $20,000
D) $80,000