Answer:
c. None of the above
Step-by-step explanation:
The equation is:
H₃O⁺ + CH₃COO⁻ ⇒ CH₃COOH + H₂O
An acid is a species that donates a proton. Thus, the acid is the species on the reactants' side that has one proton more than it's conjugate base species on the products's side.
The available options are:
a. CH₃COOH
b. H₂O
c. None of the above.
Both CH₃COOH and H₂O are on the right-hand side of the equation, so the answer must be c. The answer to the problem is H₃O⁺, since it has lost a proton and become H₂O.