Which of the Following Is a Reason Why the Euro

Which of the following is a reason why the euro has not gained more on the dollar in terms of world usage during its first 10 years?

A) International investors were unwilling to diversify their portfolios with euros because there was much speculation that the European Union will dissolve within a decade.
B) While the U.S.government is the single issuer of its public debt, each member of the European Union issues its own debt.The smaller market for each country's debt, each with different risk premiums, makes them less liquid, especially in difficult financial times.
C) Many member countries of the European Union, concerned that they may not be able to pull out of a national economic crisis without the ability to devalue their national currencies and encourage exports, conducted a sizeable volume of foreign transactions in the US dollar.
D) High rates of structural unemployment in many participating countries and a decentralized tax system prevented the euro from being a premier currency in the international financial market.