How did the attack on pearl harbor caused the us to abandon its neutral position on the war between the allies andaxis powers?

The attack on Pearl Harbor was a turning point for the United States in the World War II as it was finally pushed into the war by the Japanese bombardment of its navel base. Because Japan was part of the Axis this attack was taken as an act of aggression by the Axis powers and so the United States entered the war on the Allies side. The US could not stay out of war as it has been attacked.

After Pearl Harbor was bombed by the Japanese the United States could no longer maintain a neutral position on the war between the Axis and the Allies. As Japan was a part of the Axis Powers, the United States, taking the bombing as an act of war, abandoned it's neutral position and joining the Allied forces in World War II

Im pretty sure the answer is d.) is more densely populated.