The Reaction HCl $\to$ H⁺ + Cl^- in the Human Stomach Is an Example

The reaction HCl $\to$ H⁺ + Cl^- in the human stomach is an example of the

A) cleavage of a hydrophobic bond.
B) formation of a hydrogen bond.
C) elevation of the pH of the stomach.
D) formation of ions by dissolving an acid.
E) formation of polar covalent bonds.