Which of the Following Is True

Which of the following is true?

A) If an exchange rate is allowed to vary across a fixed basket of currencies,it is called a hard peg.
B) If an exchange rate is not allowed to vary against the target currency,it is called a soft peg.
C) If an exchange is only allowed to fluctuate within a set band,it is considered to be a flexible exchange rate system.
D) A soft peg is when a currency's exchange rate is only allowed to fluctuate within a set band.
E) Any exchange rate policy other than completely flexible exchange rate systems is extremely uncommon today for currencies.