Assertion (A): The boiling point of water decreases as the altitude increases. Reason (R): The atmospheric pressure increases with altitude.

1. Assertion (A): The boiling point of water decreases as the altitude increases. This statement is true. Water boils when its vapor pressure equals the surrounding atmospheric pressure. At higher altitudes, the atmospheric pressure is lower, so water boils at a lower temperature. 2. Reason (R): The atmospheric pressure increases with altitude. This statement is false. Atmospheric pressure decreases with increasing altitude because there is less air mass pressing down from above. 3. Since the Reason (R) is false, it cannot be the correct explanation for the true Assertion (A). The correct explanation is that atmospheric pressure *decreases* with altitude, leading to a lower boiling point. 4. Therefore, Assertion (A) is true but Reason (R) is false.