In the context of the General Data Protection Regulation (GDPR), a multinational corporation is found to be in severe violation of data protection principles, leading to a significant breach affecting millions of EU citizens' personal data. The corporation has an annual global turnover of €500 million. Considering the GDPR's enforcement mechanisms and the need to ensure compliance while balancing the corporation's ability to operate, what is the maximum fine that can be imposed under such circumstances? Choose the best option.