Consider an Acetate Buffer, Initially at the Same PH as Its

Consider an acetate buffer, initially at the same pH as its pK_a (4.76) . When sodium hydroxide (NaOH) is mixed with this buffer, the:

A) pH remains constant.
B) pH rises more than if an equal amount of NaOH is added to an acetate buffer initially at pH 6.76.
C) pH rises more than if an equal amount of NaOH is added to unbuffered water at pH 4.76.
D) ratio of acetic acid to sodium acetate in the buffer falls.
E) sodium acetate formed precipitates because it is less soluble than acetic acid.