Which of the Following Statements Is Incorrect

Which of the following statements is incorrect?

A) Governments affect foreign exchange rates indirectly by altering prevailing interest rates within their own countries.
B) Foreign currency exchange rates vary with the day-to-day demand and supply of the two foreign currencies.
C) Central governments can intervene in foreign exchange markets directly and value their currency at high rates relative to another currency.
D) All of these choices are correct.