Answer: Eastern Fleet
Ranger was the first purpose built aircraft carrier in the US Navy. Commissioned in June 1934, she was closer in size to the pioneering USS Langley than the much larger Lexington and Saratoga, and was also significantly slower, also lacking torpedo protection. Although Ranger served in the Pacific during the pre-war period, in January 1939 she left San Diego to undertake operations in the Caribbean based at Guantanamo Bay in Cuba, before proceeding to Norfolk to take up station with the Atlantic Fleet. It was while based in Virginia that Pearl Harbor was attacked - the loss of almost all of the Pacific Fleet's battleships led to a need for more aircraft carriers to be sent to Hawaii. However, Ranger's limitations in terms of size, speed and protection led to her being left in the Atlantic Theater.
In April 1942, Winston Churchill sent a message to President Roosevelt requesting reinforcement of the Royal Navy's Eastern Fleet, at the time stationed in Ceylon, following the Indian Ocean Raid, in which the Japanese had attacked British shipping and bases in the region. This had resulted in the loss of three major British warships, the heavy cruisers HMS Dorsetshire and HMS Cornwall, and the aircraft carrier HMS Hermes. Churchill requested that the US send Ranger, plus the battleship USS North Carolina, to reinforce the Eastern Fleet. Admiral Ernest King, the US Chief of Naval Operations, was adamant that no major US fleet unit, especially Ranger, be sent to the Indian Ocean, and drafted a response to Churchill's request bluntly stating this. In an effort to maintain diplomacy, President Roosevelt amended this to play up Ranger's deficiencies, with instead the ship being used to ferry fighters for the 10th Air Force based in India.