Final answer:
Among the listed options, 'Her successful military campaigns against neighboring states' is the least supported descriptor of Empress Wu Zetian's reign due to the lack of specific detailed evidence, making it the likely correct answer to the question.
Step-by-step explanation:
The question asks which of the following does not describe Empress Wu Zetian's reign. Reviewing the historical facts about Empress Wu, each option can be considered:
- Her role as the only female emperor of China: Empress Wu Zetian was indeed the only female emperor in Chinese history, founding her own dynasty, the Wu Zhou.
- Her significant expansion of the Chinese bureaucracy: She promoted the use of civil service examinations and hoped to promote talented men from lower-ranked aristocratic families through a meritocratic process, thereby expanding the bureaucracy.
- Her successful military campaigns against neighboring states: Empress Wu maintained control and power, including through military campaigns, although specific military achievements are not detailed in the provided information.
- Her promotion of Buddhism and the construction of Buddhist temples: Empress Wu was a devout Buddhist. She made Buddhism the state religion and was involved with the construction of Buddhist temples.
Given these points, all the options provided in the question accurately describe aspects of Empress Wu's reign except for her 'successful military campaigns against neighboring states', which lacks detailed evidence in the provided information and therefore may not be the best descriptor of her reign compared to the well-documented other aspects.