The correct answer is B) Rain and poor visibility. Nimbostratus clouds are low-lying, gray clouds that often produce continuous rain or drizzle, resulting in poor visibility. The appearance of nimbostratus clouds near a ship at sea would be accompanied by rainy conditions and reduced visibility, but not necessarily high winds, severe thunderstorms, or significant changes in barometric pressure and wind direction. The other answer choices are incorrect because they do not accurately describe the weather conditions typically associated with the presence of nimbostratus clouds. High winds and rising seas (A) are not directly linked to nimbostratus clouds, severe thunderstorms (C) are not a common occurrence with this cloud type, and dropping barometric pressure with backing wind (D) are more characteristic of other cloud formations.