Which of the following has highly acidic hydrogen?

Acidic hydrogen is a hydrogen atom in an acid that dissociates to generate a positive ion.

After removal of ${\mathrm{H}}^{+}$ion, the negative charge is formed. The more stable the negative charge, the more will be the acidic strength.

Due to cross conjugation of negative charge, it is
most stabilised anion.

Hence, the answer is option D.