D-The Soviet government used fear and terror to control its citizens.
Explanation:
The people of the Soviet Russia, even the ones at the top positions were easily living in the reign of terror where even incidents such as this were worthy of sending them to prison.
This incident is basically where the first person who stops clapping is the one who gets to be known as a traitor for the people as that person does not care about the regime enough.
Now this incident clearly shows that the Soviets had taken this to an extreme and even something as silly could land you in prison for a long time.
