Why Is It Difficult for a Government to Avoid a Currency

Why is it difficult for a government to avoid a currency crisis?

A) Important companies that have borrowed in foreign currencies can be a powerful lobby in favor of abrupt devaluations of the currency in order to reduce their debts.
B) Exporters clamor for the government to maintain overvalued exchange rates when the currency should be devalued.
C) International investors are easily alarmed by any sign of instability and are quick to sell off currency.
D) In democracies,government officials have to worry about the votes of consumers who would be hurt by overvalued exchange rates.