To increase royal power, French kings primarily took actions that included winning the support of the church, building a bureaucratic system, and fostering relationships with various social classes, including the middle class. Therefore, the most accurate answer among the options provided is:
B. Won support of the church, built bureaucracy, antagonized the middle class.
This option indicates their efforts to consolidate power through alliances with the church and creating a structured administration, though antagonizing the middle class could lead to resistance in the long term.