Members of the Executive Council must be which of the following?

Members of the Executive Council in Hong Kong must be Chinese citizens. This requirement is rooted in the principles laid out in the Basic Law of Hong Kong, which establishes the framework for the region's political structure and governance. The emphasis on Chinese citizenship underscores the importance of loyalty to the Central People's Government and the sovereignty of China over Hong Kong.

Having members who are Chinese citizens ensures that the Executive Council, which serves as a key decision-making body advising the Chief Executive, aligns with the policies and legal frameworks of the People's Republic of China. This reflects the larger context of national security and governance principles, which are essential in maintaining stability and promoting the interests of the state within the framework of "one country, two systems."

The other options relate to individuals who do not meet this specific criterion. Foreign nationals and foreign diplomats, for instance, do not have the legal tie to the sovereignty of China that Chinese citizens possess, making them unsuitable for roles that require a commitment to Hong Kong's unique blend of local governance and national obligations. Permanent residents may not necessarily be Chinese citizens, thus failing to fulfill the requisite requirement for membership in the Executive Council.