Question 1318Navigation General

The correct answer is C) deteriorating or unsettled weather. A slow, gradual fall of the barometer indicates that the atmospheric pressure is dropping, which is typically a sign of an approaching weather system that will bring deteriorating or unsettled weather conditions. This includes the potential for things like increased cloud cover, wind, rain, or other inclement weather. The other answer choices are incorrect because they are more specific weather phenomena that may or may not necessarily accompany a gradual barometer drop, whereas deteriorating or unsettled weather is the broader, more accurate descriptor for the atmospheric conditions suggested by a slowly falling barometer.