Trying to figure out how to calculate preferred dividends with this information! Please help!

Standard Electronics Standard Electronics Balance Sheet Balance Sheet As of December 31, 2019 As of December 31, 2018 Total Assets $578,000 $499,000 Total Liabilities 330,000 284,000 Total Stockholders' Equity (all common) 248,000 215,000 Total Liabilities and Stockholders' Equity $578,000 $499,000 Net income for 2019 was $20,000. Compute the rate of return on common stockholders' equity for 2019. (Round your final answer to two decimal places.) O A. 8.06% O B. 3.71% O C. 3.46% O D. 8.64%