Aspartic Acid (C₄H₇NO₄), One of the 20 Essential Amino Acids

Aspartic acid (C₄H₇NO₄) , one of the 20 essential amino acids, has two ionizable hydrogens.At 25°C, K_a1 = 1.38 × 10^-4 and K_a2 = 1.51 × 10^-10.What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid?

A) 3.33 × 10^-2 M
B) 4.16 × 10^-3 M
C) 4.15 × 10^-3 M
D) 1.51 × 10^-10 M
E) 2.08 × 10^-14 M