Answer:
20th century
Step-by-step explanation:
The 20th century has seen a drastic change in the history. It is the most crucial and important century in the history of mankind.
It is also considered to be the most violent in the entire history. It had witness two world wars and a long stretched cold war. Many dictators such as Hitler, Pol Pot, Stalin, etc have invented and established Totalitarian state.
Through the 20th century alternative styles of arts have changed with the increasing speed.
Thus the answer is 20th century.