What Is the Definition of a Party "Boss

What is the definition of a party "boss"?

A) An absolute political leader who uses his "machine" to govern local politics, promoting personal and party interests
B) The name given to a leader and scholar who studies and promotes the ideas of social Darwinism
C) A union leader who organizes social activities for members and fights for better representation of workers
D) A political leader who represents a rural area and refuses to associate with or participate in the corruption of the city
E) A business tycoon who dominates trade but refuses to interact with politicians because it is more advantageous for him to keep those spheres separate