Lactic Acid Is a Major Component of Ringer's Solution, Which $\times$

Lactic acid is a major component of Ringer's solution, which is used as an intravenous fluid to maintain fluid balance in trauma patients. The pH of a 0.100 M lactic acid solution is around 2.44. Based on this information, determine the value of the acid ionization constant, K_a, for lactic acid.

A) 1.2 $\times$ 10^-2
B) 1.4 $\times$ 10^-4
C) 4.7 $\times$ 10^-3
D) 1.8 $\times$ 10^-4
E) 7.4 $\times$ 10^-3