What is the largest unit of geologic time

The geologic history of the Earth is broken up into hierarchical chunks of time. From largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages. 

A,b,c is the answer to the question

Africans learned what the europeans wanted them to learn. instead of learning about african history and current information that could and would them they learned solely what europe wanted them to. and not everyone received the same education, some received better and others none.