Option 1 -> The Euro can be traded outside the country, giving it international liquidity and broader market access.
Option 2 -> While the Euro is traded in the USA, this alone doesn't explain why other currencies would be jealous.
Option 3 -> Being placed in a Federal Bank is not a unique advantage that would make other currencies jealous.
Option 4 -> Having secrets to reveal is not a legitimate economic advantage for a currency.
Hence, Option 1: Euro can be traded outside the country -> The Euro's ability to be freely traded internationally gives it significant advantages in global commerce, making it more versatile and widely accepted than currencies with restricted trading capabilities. This international tradability enhances its value and utility in the global financial system. -> correct