Answer: d. The US used airplanes and aircraft carriers against Japan.
Step-by-step explanation:
After the American expulsion from the Philippians, the Americans decisively deafeated the Japanese in the Battle of Midway and sank 4 of their Aircraft Carriers which Japan proved unable to replace for the entirety of the war. From here on out the Americans used this to their advantage by gaining and maintaining air superiority in every battle against the Japanese.
Using Aircraft carriers and Airplanes, they would attack weakly defended islands and occupy them then turn the Islands into Air-force basis themselves to be used for further air attacks. This strategy continued till August 6 and 9, 1945 when separate B-29 bombers dropped the atomic bombs on Hiroshima and Nagasaki and forced the Japanese to surrender.