Which position has always been held concurrently by the Vice President since the early 1990s?

The Vice President of China has always served concurrently as a key figure in the country's political system, which is the President. Since the early 1990s, the role of Vice President has been closely linked to the presidency, especially in providing continuity in leadership and governance. This concurrent holding of positions enhances the Vice President's influence and allows for a smoother transition of power within the upper echelons of the Chinese Communist Party.

In the case of the other options, the Premier is typically a separate role focused on the administration and government operations, while the Minister of Defense and the Chairman of the Standing Committee represent distinct areas of governance and do not have a historical pattern of being held concurrently by the Vice President. Thus, the connection of the Vice Presidency with the presidency reflects the centralization of power in the Chinese political system, reinforcing the significance of the presidency as the top leadership position.