The correct answer is: A. fall in exchange value of a country by market forces.
Devaluation of a currency is a decrease in the value of a currency relative to other currencies. It can happen when the market forces of supply and demand cause the price of a currency to fall. This can be due to a number of factors, such as a country’s economic performance, political stability, or interest rates.
Devaluation can make a country’s exports more competitive, as they will be cheaper for foreign buyers. However, it can also make imports more expensive, which can lead to inflation.
B. reduction in external value/exchange value of currency by the government is not always considered devaluation. It is called devaluation when the government takes active measures to reduce the value of its currency, such as by selling its own currency on the foreign exchange market.
C. reduction in currency value due to wear and tear is not considered devaluation. This is because the value of a currency is not determined by its physical condition, but by its purchasing power.