Final answer:
The rate at which one currency is exchanged for another is known as the foreign exchange rate. It is used as a common denominator for international trade and comparative GDP analysis. The regime where currencies fluctuate within margins is known as a floating exchange rate.
Step-by-step explanation:
The rate at which one currency is converted to another is called the foreign exchange rate. When we talk about converting currencies to compare GDP, or trade goods across countries, we use the foreign exchange rate as a common denominator. This rate expresses the value of one currency in terms of another currency, such as Japanese yen per British pound or vice versa. There are different types of exchange rates, such as market exchange rates and purchasing power parity (PPP).
On the matter of exchange rate regimes where governments allow their currencies to fluctuate within margins, the accurate term is floating (flexible) exchange rate. Option 'b' would be the correct choice in that context. This contrasts with a fixed (pegged) exchange rate where a currency's value is tied to another major currency or basket of currencies.
The rate at which one currency is converted to another currency is called the foreign exchange rate. It is the value of one country's currency in terms of another country's currency. Foreign exchange rates can be expressed as the units of one currency that need to be traded for a single unit of another currency.