At present, approximately how many years would it take for the world's population to double?

With respect to prices, at the macroeconomic level attention is focused on relative prices, while at the microeconomic level attention is focused on absolute prices

Indicate whether the statement is true or false

Suppose a currency's value in the foreign exchange market is determined solely by market supply and demand without any intervention by the government authority, the currency has

A) a fixed exchange rate. B) a gold standard. C) a price control in its exchange rate. D) a floating exchange rate.