Answer :
The attack on Pearl Harbor changed the public's opinion about the war in that the attack convinced Americans that force was necessary to stop Japan's aggression.
The correct ansswer is The attack convinced Americans that force was necessary to stop Japan's aggression.
Before the attack on Pearl Harbor, the US wanted to stay out of World War II. Many citizens followed an isolationist policy. This meant that they did not want the US government to send troops to Europe or Asia during this time. This isolationist sentiment was influenced by America's participation in World War I.
However, this all changed after the Japanese military attacked a US military base in Hawaii. The next day, the US officially declared war on Japan and entered World War II.