How are hydronium ions (H₃O⁺) and hydroxide ions (OH^-) formed during the auto-ionization of water?

• A. One water molecule donates a proton to another, forming H₃O⁺ and OH^-.
• B. Water molecules split into hydrogen and oxygen gas.
• C. Water molecules absorb energy and form ions.
• D. Water molecules react with carbon dioxide to form ions.

Answer: (A)