It's very cold.

The dangers that expedition members may encounter in the Antarctic are: the snowstorm is coming and they can't see the road clearly; Snow covers the ice gap and may engulf the players at any time; The cold weather left the players with ruthless frostbite; There is no country or settled population in Antarctica, so you may not meet researchers from different countries in the Antarctic region. Blizzard is coming, and you can't see the route clearly; The polar bear is a representative animal in the Arctic.

So choose: a.