Why might a single objective of price stability be easier for the ECB to fulfil given its circumstances? OA. The European Central bank covers multiple countries with differing employment goals while the Federal Reserve is responsible for a unified system with a common employment goal. OB. The European Central bank is responsible for a single economic bloc while the Federal Reserve is responsible for multiple states with differing employment goals. OC. Employment goals are more difficult to achieve. OD. Price stability is easier to achieve.