An pharmaceutical industry analyst gathers the following information about a company during 2011. The net income is $23000. The total assets are $140000 on January 1, 2011. The total assets are $180000 on 31 December, 2011. The cash dividends paid on common stock this year are $8000, and the financial leverage is 2.5. The company's sustainable growth rate is closest to:（）
A. 9.4%
B. 20.8%
C. 23.4%
