The correct answer is Option A) Pearl Harbor
Osami Nagano was the Imperial Japanese Navy General Staff during the World War II.
The United States could have proven to be a huge problem for Japanese forces, due to the former's Pacific Fleet.
In order to completely handicap the United States Pacific Fleet, a plan was devised for a surprise attack on Hawaii's Pearl Harbor. From a tactical point of view, the plan was executed perfectly as the Japanese were able to destroy a large part of the America's Pacific Naval power.
Strategically, it was seen as a disaster as the US was, before the attack, keeping an isolationist policy in World War II and did not have intention of entering any world conflict.