Detailed Instructions: In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.
Problem:Question: When were the IXB submarines entered into service? Passage 1:USS Castle Rock (AVP-35) was a United States Navy Barnegat-class small seaplane tender in commission from 1944 to 1946 which saw service in the late months of World War II. After the war, she was in commission in the United States Coast Guard as the Coast Guard cutter USCGC Castle Rock (WAVP-383), later WHEC-383, from 1948 to 1971, seeing service in the Vietnam War during her Coast Guard career. Transferred to South Vietnam in 1971, she served in the Republic of Vietnam Navy as the frigate RVNS Trần Bình Trọng (HQ-05) and fought in the Battle of the Paracel Islands in 1974. When South Vietnam collapsed at the end of the Vietnam War in 1975, Trần Bình Trọng fled to the Philippines, where she served in the Philippine Navy from 1979 to 1985 as the frigate RPS (later BRP) Francisco Dagohoy (PF-10).
 Passage 2:German Type IXC submarines were slightly larger than the original Type IXBs. U-154 had a displacement of when at the surface and while submerged. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
 Passage 3:Stevens was a firm supporter of former brigadier general Franklin Pierce's candidacy for President of the United States in 1852, as both men had served in the Mexican–American War. Stevens was rewarded by President Pierce on March 17, 1853 by being named governor of the newly created Washington Territory. (The position also included the title of Superintendent of Indian Affairs for that region). Stevens chose to add one more duty as he traveled west to the territory he would govern: the government was calling for a surveyor to map an appropriate railroad route across the northern United States, hoping that a transatlantic railroad would open up Asian markets. With Stevens' engineering experience (and likely the favor of Pierce yet again, as well as Secretary of War Jefferson Davis), he won the bid. His party, which included Dr. George Suckley, John Mullan and Fred Burr, son of David H. Burr, spent most of 1853 moving slowly across the prairie, surveying the way to Washington Territory. There Stevens met George McClellan's party, which had surveyed the line between the Puget Sound and the Spokane River. He took up his post at Olympia as governor in November that year.

Solution:
2