In the mid-20th century, when many countries left the gold standard created an increase in the demand for US dollars.
Option D is the correct answer.
A gold standard is a kind of monetary method where a currency of a country is treated as equivalent to the price of gold.
In the year 1931, the country of Japan and Great Britain, and many other countries were left the gold standard due to which the US country In the year 1933 fixed a higher dollar price for gold that is $35 per ounce. This leads to an increase in demand for US dollars.
Therefore, the demand for US dollars increased when the countries left the gold standard,
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