The correct answer is Russian Revolution
The Russian Revolution of 1917 was one of the main events of the 20th century. This event broke out during the First World War (1914-1918), despite its antecedents going back to 1905, when the first revolutionary attempt took place, which had as its trigger the remarkable episode known as Bloody Sunday.
The main aspect of the Russian Revolution is that it was guided by communist doctrine, developed by the German philosopher Karl Marx in the 19th century - with the proviso that such doctrine was complemented and added to a strategic plan by the one who became the most important leader of the revolution: Lenin.
I'm not 100% sure this is the answer but I know they were successful in math.
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The answer is c because they give unlimited amounts is of money
Filial Piety was an idea in Confucian philosophy where elders were meant to be respected the most.
It is something that is still held to majority of Asian society in which the children of the family would respect the elders the most, for instance, the grandchild and the grandmother would have the grandmother respected the most and so on throughout the family tree.
Hope this helps!