Snow has obliterated surface features and the sky is covered with uniform, altostratus clouds. There are no shadows and the horizon has disappeared. What is this condition called?

Correct Answer: Option A — Whiteout

A whiteout occurs when uniform altostratus cloud cover combines with snow-covered terrain, eliminating shadows, contrast, and the visible horizon. This optical phenomenon severely impairs depth perception and spatial orientation for navigators operating in polar regions.