Since PK_a = -Log K_a, Which of the Following Is

Multiple Choice

Since pK_a = -log K_a, which of the following is a correct statement?

A) acetic acid (pK_a = 4.7) is stronger than lactic acid, (pK_a = 3.9)
B) lactic acid, (pK_a = 3.9) is weaker than all forms of phosphoric acid, (pK_a = 2.1, 6.9 and 12.4)
C) since the pK_a for conversion of the ammonium ion to ammonia is 9.25, ammonia is a weaker base then the acetate ion
D) for carbonic acid with pK_a values of 6.3 and 10.3, the bicarbonate ion is a stronger base than the carbonate ion
E) none of the above