That which is an important cause of inflation in an economy is this:
d. Growth in the quantity of money in the economy
Inflation refers to the increase in the prices of commodities in a nation. When the prizes of things increase int he economy, the probable result is that there will be a reduction in the purchasing power of the country's currency. There is a type of inflation that is known as monetary inflation. This often results in an increase in the supply of money in the economy.
The last option in the list above is an apt description of monetary inflation. When there is an increase or growth in the quantity of money in the economy, then we can say that inflation has occurred. Inflation heavily disrupts the health of an economy. So, option D describes an important cause of inflation in an economy.
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