`Remember that an acid is something that donates hydrogen ions. So, when considering the formula HC2H3O2 (acetic acid), which of the hydrogens listed are the ones that ionize (fall apart into solution as hydrogen ions)?

•  A. all 3 of the H’s on the right-side.
•  B. the H on the left.
•  C. all four H’s.
•  D. one of the H’s on the right-side.
•  E. none of the above.