Final answer:
Option 3) HNO₃ + KOH ⟶ H₂O + KNO₃ is the correct answer since it represents an acid-base neutralization reaction, where nitric acid reacts with potassium hydroxide to form water and potassium nitrate.
Step-by-step explanation:
The acid-base neutralization reaction among the options provided is 3) HNO₃ + KOH ⟶ H₂O + KNO₃. In a neutralization reaction, an acid reacts with a base to produce water and a salt.
Here, the strong acid, nitric acid (HNO₃), and the strong base, potassium hydroxide (KOH), interact to form water (H₂O) and a salt, potassium nitrate (KNO₃).
Other options do not represent neutralization reactions as they do not produce water and a salt from the reaction of an acid and a base.