Answer:
C. an attempt to overthrow communist rule in Hungary
Step-by-step explanation:
The Hungarian flag was bearing the Rakosi coat of arms, reflecting the communist rule in Hungary. The Hungarians though despised the Soviets and being under their control, so they made a revolution. The Hungarian Revolution had its own flag, and the flag was totally the same, apart from the Rakosi coat of arms being cut off from it, thus having a white gap in he center. The meaning of this feature on the flag was that the Hungarians want to overthrow the communist rule in the country, and that the communism and the Soviet rule doesn't have place in their society.