By each of those colonies working together to secede from the British Empire.
Had to look for the options and here is my answer.
Chief Justice Earl Warren is known as the former governor of California and under his leadership, the Supreme Court focused on the said issues but one which is the overturning the precedent of "separate but equal". This is with regards to school segregation. Hope this helps.
Pearl Harbor. The atomic bombs that we dropped on Japan was revenge for Pearl Harbor. We already had some issues with Japan but the surprise attack on Pearl Harbor was the main reason for the atomic bombs that President Truman dropped on Japan.
The answer is A. -- El Coliseo