For her son's tuition fee, Maria borrowed 10 000 pesos from a lending company with annual simple interest rate of 8.4%. If she had not given any interest before, how much should she pay the company to pay off her debt after 2 years?
A.1 680 pesos
B.16 800 pesos
C.26 800 pesos
D.11 680 pesos
E. None of these