The correct answers are:

✅ A. Advanced currency management is deactivated
✅ B. Price book entries are missing EUR prices

Explanation:
When working in multiple currencies in Salesforce, several components must align for a sales rep to see prices in the correct currency.

✅ A. Advanced currency management is deactivated
If Advanced Currency Management is not enabled, Salesforce cannot track dated exchange rates or handle complex scenarios where product prices vary over time by currency. While not always necessary, its absence can cause issues in environments with time-sensitive or region-specific pricing.

✅ B. Price book entries are missing EUR prices
Even if multi-currency is enabled, each product must have price book entries in the correct currency. If EUR prices are missing from the relevant price book, users won't be able to add products in EUR.

It’s BC

The opportunity has to be the same as price book entry

I think this answer will be B,D.