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: How long had Ferdinand I ruled for by the year Lamego fell? Passage 1:It would seem that Gill's interests lay elsewhere since after a few years he sold the business, and then spent time equipping Lord Lindsay's private observatory at Dun Echt, Aberdeenshire. In 1874, Gill joined the expedition to Mauritius to observe the transit of Venus. Three years later he went to Ascension Island to observe a near approach of Mars and to calculate its distance. While carrying out these laborious calculations, he was notified of his appointment to the Cape Observatory, which, over the following 27 years he was to refurbish completely, turning it into a first-rate institution. Gill was a meticulous observer and had a flair for getting the best out of his instruments. His solar parallax observations with a heliometer and his calculations of distances to the nearer stars, are testimony to his outstanding work. He recruited Robert Innes to the Cape Observatory.
Passage 2:Irish stars Jimmy Clausen and Golden Tate chose to forgo their final years of eligibility and declare for the 2010 NFL draft. The Irish also lost a number of seniors to graduation, including linemen Eric Olsen, Paul Duncan and four-year starter Sam Young. Other notable losses included running back James Aldridge, wideout Robby Parris, and George West on offense. On defense, ND lost senior captains Kyle McCarthy and Scott Smith, Raeshon McNeil, Sergio Brown, John Ryan and Ray Herring to graduation. Standout special teams player Mike Anello also finished his final year of eligibility. Sophomore defensive back E.J Banks left the team in August 2010, but will still be enrolled at the school. On August 31, within days of the September 4 season opener against Purdue, sophomore wide receiver Shaquelle Evans was granted his release from the team, and decided to enroll at UCLA. Freshman Derek Roback also left the program in early September, as his desire to play quarterback led to his transfer to Ohio
Passage 3:The history of the county of Portugal is traditionally dated from the reconquest of Portus Cale (Porto) by Vimara Peres in 868. He was named a count and given control of the frontier region between the Limia and Douro rivers by Alfonso III of Asturias. South of the Douro, another border county would be formed decades later when what would become the County of Coimbra was conquered from the Moors by Hermenegildo Guterres. This moved the frontier away from the southern bounds of the county of Portugal, but it was still subject to repeated campaigns from the Caliphate of Cordoba. The recapture of Coimbra by Almanzor in 987 again placed the County of Portugal on the southern frontier of the Leonese state for most of the rest of the first county's existence. The regions to its south were only again conquered in the reign of Ferdinand I of Leon and Castile, with Lamego falling in 1057, Viseu in 1058 and finally Coimbra in 1064.

Solution:
3