Final answer:
The East German communist leaders were overthrown by peaceful protests and mass demonstrations, part of a broader movement of peaceful revolutions across Eastern Europe facilitated by citizens' empowerment and the Soviet Union's non-intervention stance.
Step-by-step explanation:
The East Germans overthrew their communist leaders through A) Peaceful protests and mass demonstrations. In November 1989, the Berlin Wall came down as a result of peaceful demonstrations that had been building for months. These were part of a larger movement across Eastern Europe, leading to the downfall of Communist governments, most of which occurred without violence.
Key factors in this peaceful transition included democratic reforms, public uprisings, and the Soviet Union's decision under Mikhail Gorbachev not to use military force to suppress the movements. While most Eastern European revolutions, such as the Velvet Revolution in Czechoslovakia, were peaceful, Romania was an exception where a violent overthrow occurred, and leader Nicolae Ceausescu was executed.
Overall, it was the empowerment of citizens and grassroots efforts that propelled the revolutions, leading to the establishment of parliamentary democracies and the participation even of former Communist parties in free elections.