The correct answer is B, as the first major Pacific battle of World War II was the Battle of Midway.
The Battle of the Midway was fought between June 4 and 6, 1942, during the Second World War: the United States Navy repelled the attack of the Japanese Imperial Navy near the Midway Islands. The Americans sank four large Japanese aircraft carriers and thus marked a turning point in the Pacific war with the stop of the Japanese advance. With the subsequent campaign of Guadalcanal the allied counter-offensive and the slow retreat of Japan would begin.
Fought only a month after the Battle of the Coral Sea, Midway was the second naval battle in history almost completely fought by the air forces on aircraft carriers, with no visual contact between opposing fleets and no firefighting between liners.
The serious Japanese losses of precious aircraft carriers and trained pilots blocked their further advance and allowed the American forces to move to the counteroffensive, thanks to the arrival of new ships and new aircraft produced by their powerful industrial production.