Which of the following describes the way reform was brought to Tammany Hall?

A.
Inside leaders such as Charles Murphy launched their own reform efforts.

B.
Aggressive muckrakers such as Upton Sinclair undermined their control.

C.
Political upstarts such as Hazen Pingree used democracy to overwhelm the machine.

D.
Intellectuals such as Grover Cleveland united businessmen with reform groups.