In the early 1930s, the American foreign policy was isolationist

In the early 1930s, the American foreign policy was isolationist, but the ______ suddenly changed the whole situation, which propelled the U.S. into the Second World War.
A、Pearl Harbor attack
B、bombing of Guam island
C、seizing of American merchant ships
D、sinking of American passenger ships
【正确答案】：A
【题目解析】：本题考查第二次世界大战时的美国。根据课本P212可知，20世纪30年代初，美国的外交政策是孤立主义的，但是珍珠港事件突然改变了整个局势，把美国推入了第二次世界大战。