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: What was the population of Hertford in 1835? Passage 1:In 1835, Cowper was elected Liberal Member of Parliament for Hertford, a seat he held for the next thirty-three years, and became private secretary to his uncle Prime Minister Lord Melbourne. He was appointed a Groom in Waiting in 1837, and in 1841 served for three months as a Lord of the Treasury under Melbourne, only resuming office five years later as a Lord of the Admiralty when the Whigs returned to power under Lord John Russell. He again held this post under Lord Aberdeen from 1852 to 1855, and in the latter year was made Under-Secretary of State for the Home Department by his stepfather Lord Palmerston when he became Prime Minister. In August that same year he was appointed President of the Board of Health, and sworn of the Privy Council. Four years later he became Vice-President of the Board of Trade and Paymaster General, only serving for a year before Palmerston appointed him First Commissioner of Works.
 Passage 2:Franz Burgmeier (born 7 April 1982) is a Liechtenstein retired footballer, who played as a midfielder for Vaduz in the Swiss Super League. Born in Triesen, Burgmeier was a burgeoning footballer and keen skier, until he gave up the latter sport at 16 following a serious injury. Having been a youth player for Triesen, he started his professional career with Vaduz. Burgmeier won several Liechtensteiner Cups with Vaduz, who were promoted to the Swiss Challenge League in 2001, and played in the UEFA Cup. After two unsuccessful attempts to win promotion to the Swiss Super League, Burgmeier left for Aarau in 2005. He spent only one season with Aarau before a move to the previous season's runners-up Basel in 2006. His two seasons with Basel were broken up by a loan spell with Thun, before he moved to England with Darlington in August 2008, where he played for one year.
 Passage 3:In early 1920 he commanded a military mission which supervised the withdrawal of Romanian Forces left in Hungary after the Hungarian–Romanian War of 1919, and in the summer was attached to the force occupying İzmit, Turkey, as it prepared to withdraw. His third overseas posting of the year was to Persia in late August, where – among other things – he appointed Reza Khan (after ousting the Russian officer Vsevolod Starosselsky and having his offered position declined by Sardar Homayoun) to command the élite Cossack Brigade; Reza Khan would later seize control of the country, and rule as Shah from 1925 to 1941. The precise level of British involvement in Reza Khan's coup remains a matter of historical debate, but it is almost certain that Ironside himself at least provided advice to the plotters. On his departure from Persia in 1921, the Shah awarded him the Order of the Lion and the Sun.

Solution:
1