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.
Q: Question: What army did the 13th Iowa Infantry Regiment fight for during the Civil War? Passage 1:Ryan supports eliminating the capital gains tax, the corporate income tax, the estate tax, and the Alternative Minimum Tax. In 1999, Ryan supported the Gramm–Leach–Bliley Act, which repealed some financial regulation of banks from the Glass–Steagall Act of 1933. During the economic recovery from the Great Recession of the late 2000s, Ryan supported the Troubled Asset Relief Program (TARP), which authorized the Treasury to purchase toxic assets from banks and other financial institutions, and the auto industry bailout; Ryan opposed the Credit CARD Act of 2009, which expanded consumer protections regarding credit card plans, and the Dodd–Frank Wall Street Reform and Consumer Protection Act, which strengthened financial regulation.
 Passage 2:He first appears in Constantinople in 1401, qualified as an oikeios of the emperor. In 1417 he was possibly sent on a diplomatic mission to the Venetians in the Morea. In 1422 and again in 1429 he was sent by Emperor John VIII Palaiologos as an envoy to the Ottoman Sultan Murad II. At the time he had the relatively lowly rank of protovestiarites, but was quickly promoted to protostrator and then to the senior rank of megas stratopedarches, which he held already during his mission in 1430 to Pope Martin V. During his return from the mission to the Pope, on orders from the Emperor, he raised Thomas Palaiologos to the rank of Despot in the Morea. He led two more missions abroad, one in 1433 to Pope Eugene IV, and one in 1438 to Venice.
 Passage 3:At the beginning of the Civil War, he became a lieutenant and adjutant of the 13th Iowa Infantry Regiment. He fought at the battle of Shiloh and Corinth. He served as assistant adjutant general in the XVII Corps during the siege of Vicksburg and assistant adjutant general to the Army of the Tennessee during the Atlanta Campaign. He was made a brevet brigadier general for service in the Atlanta Campaign and was assigned to an infantry brigade in the XV Corps during the Carolinas Campaign, but was only lightly engaged in fighting. He rose to the full rank of brigadier general of volunteers (1865), and was made a brevet major general at the close of the same year for gallant and meritorious services during the war.

A:
3