The correct answer is B) Aircraft carriers.
The target that was not present at Pearl Harbor that proved important in the war in the Pacific was aircraft carriers.
The Japanese Air Force could not completely destroy the US fleet. Their bombers missed important targets such as US aircraft carrier that was not on the island at that precise moment. The Japanese also missed oil tanks and ammunition warehouses.
The Japanese were able to surprise the US at Pearl Harbor because Japanese aircraft carriers had approached Hawaii unnoticed.
The Pearl Harbor attack happened on December 7, 1941, during World War II. The United States had maintained its distance from the European conflict due to the policy of neutrality installed by US President Woodrow Wilson. However, after the attack, President Wilson asked Congress for a declaration of war and that is how the United States entered World War II.