The 2018 balance sheet of E.I de Pont de Nemours and Company shows average DuPont shareholders' equity of $13,219 million, net operating profit after tax of $3,145 million, net income after tax of $4,848 million, and common shares issued of 1,014 million. Assume the company has no preferred shares issued. DuPont's return on equity (ROE) for the year is approximately:

A. 36.7%

B. 33.4%

C. 20.9%

D. 23.8%