Final answer:
When the euro depreciates relative to the dollar, the dollar appreciates and it takes more euros to buy a dollar, making the euro weaker and the dollar stronger in terms of exchange value. The correct answer is option C. and D.
Step-by-step explanation:
When the euro depreciates relative to the dollar, the correct statements are that the dollar appreciates relative to the euro, and it will take more euros to buy a dollar. This means that if you have euros and want to exchange them for dollars, you will receive fewer dollars for each euro you exchange, hence you need more euros to get the same amount of dollars. On the other hand, if you have dollars and want to buy euros, it will take fewer dollars to buy each euro.
In the context of international finance and currency exchange, appreciation refers to an increase in the value of a currency relative to another, while depreciation refers to a decrease. Therefore, when the euro depreciates against the dollar, the euro has become weaker in value, and conversely, the dollar has become stronger, or has appreciated, against the euro. In currency markets, this fluctuation in value can be influenced by interest rates, economic policies, and various other factors.