Select the most appropriate option to fill in the blank.
Education is one of the most important _______ of empowering women with the knowledge, skills and self-confidence necessary to participate fully in the development process.

In this context, "means" acts as a singular/plural noun signifying a method, tool, or instrument used to achieve a result. Education is a medium/tool ("means") for empowering women.
Deeds means actions; Procedures refers to established series of steps; Endeavours means attempts to achieve a goal.