For a 010 M Solution of a Weak Acid,HA,with PK_a = 10,which

For a 0.10 M solution of a weak acid,HA,with pK_a = 10,which of the following is true?

A) [HA] $\cong$ 0
B) [HA] = [A-^--]
C) [HA] = [H₃O⁺]
D) [HA] = K_a
E) [HA] $\neq$ [H₃O⁺]