due to the climate shipping cargo on the St. Lawrence seaway is impossible between November and April what kind of trade barriers is this considered

Question

due to the climate shipping cargo on the St. Lawrence seaway is impossible between November and April what kind of trade barriers is this considered
A manmade
B natural

GPT 3.5 · Answer

This trade barrier can be considered a natural trade barrier. This is because it is caused by the natural condition of the climate and weather patterns in the St. Lawrence Seaway region.