Japan’s deception and successive surprise attacks revealed its aggressive stance in World War II.
Explanation:
In the given excerpt from President Roosevelt's 'Day of Infamy' speech better known as Pearl Harbor Address that was delivered on 7th of December 1941, the key idea that is discussed would be 'Japan's deception(reflected by the phrase 'attack was deliberately planned') and successive surprise attacks(exposed Japanese onslaught and wicked character while attacking Philippine, Wake, Midway, Hong Kong, Malaya, etc.) on United States' naval and military forces disclosed its hostile attitude in Second World War.' This led the United States to enter the war officially when president declared that 'all measures be taken for our defense.' Thus, option B is the correct answer.
