During an experiment, an acid (vinegar) was added at the same rate to two different liquids. Liquid A was distilled water; Liquid B was distilled water with a crushed antacid tablet stirred in. Which liquid became acidic first, as indicated by a change of litmus paper from blue to red?

A.
Liquid A became acidic first.

B.
Liquid B became acidic first.

C.
They changed at the same rate.

D.
Neither of them ever became acidic.