The answer is the letter d
Answer:
On February 4, 19 15 , Germany declared the waters about the British Isles a "war zone" in which submarines would destroy every enemy merchant vessel found there. Britain's blockade across the North Sea and the English Channel cut the flow of war supplies, food, and fuel to Germany during World War I. Germany retaliated by using its submarines to destroy neutral ships that were supplying the Allies.
Explanation:
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One way of calculating the GDP of a country is to calculate the money spent by the different groups that participate in the economy.
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