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.

Question: How long did the war that Adair served as a second lieutenant in the British Army last? Passage 1:Adair fought in the First World War. He joined the British Army, receiving his commission as a probationary second lieutenant on 2 May 1916 in the 5th (Reserve) Battalion of the Grenadier Guards. From January 1917 onwards he served in the trenches of the Western Front in France and Belgium as part of the 2nd Company, 3rd Battalion, Grenadier Guards, with the rank of lieutenant. The battalion was part of the 2nd Guards Brigade of the Guards Division. Adair's first major battle was in the pursuit of the retreating German Army to the Hindenburg Line. The division then took part in the Battle of Passchendaele. Adair, however, took no part in the battle, due to an injury sustained in a bicycle accident in early July 1917. He returned to the battalion in January 1918.
 Passage 2:Meanwhile, at Oscarsborg Fortress near Drøbak, Colonel Birger Eriksen prepares his undermanned and inexperienced garrison for combat, while receiving reports from the outlying fortresses of incoming German ships. Early on the morning of 9 April, Eriksen spots the German cruiser Blücher entering Drøbak Sound. Despite having received no instructions from Oslo to engage, Eriksen considers the German ship to be hostile and gives the order to fire, and the fortress's guns and torpedo battery sink the Blücher. Prime Minister Nygaardsvold telephones the King, informing him of the impending invasion, and advises him to flee Oslo. The Royal Family boards a train for Hamar, where the Norwegian Parliament convenes to discuss negotiations with Germany. Bräuer meets Oslo's police chief Kristian Welhaven, his intermediary with the Norwegian Cabinet, to reassure them of his desire to negotiate; at the same time, Pohlman receives orders from Berlin to send paratroopers to Hamar to capture the King and the Cabinet. Nasjonal Samling leader Vidkun Quisling proclaims himself Prime Minister over the national radio, and calls upon the Norwegian people to accept the German occupation forces. Bräuer receives instructions from Hitler himself to go directly to the King and convince him to recognise Quisling's government, though Bräuer is convinced that neither Haakon nor the Cabinet will accept this.
 Passage 3:Reg Keys was an ambulance paramedic for 19 years in Solihull before retiring to Llanuwchllyn, Bala in North Wales. In the 2005 UK general election, he stood against the then Prime Minister, Tony Blair, in the Sedgefield constituency. Keys declared at the outset of the campaign that he had been a Labour Party voter and was still basically socialist, but that he was seeking election as a candidate opposed to Blair's policy on the Iraq War. He claimed that by electing him, voters could keep the Labour Party in power but with Gordon Brown as the likely Prime Minister rather than Blair. Former Independent MP Martin Bell urged the other parties to withdraw their candidates as removing a supporter of the war from office would send a message to President Bush and other World Leaders who had supported him. During the campaign, UK newspaper The Guardian's Stuart Jeffries asked Keys, "Is it difficult to be a political candidate in these circumstances, when you are still clearly grieving?", to which he replied "Yes it is. […] I feel, though, that I have a responsibility to Tom. I keep going back to the words of a widow of a man who died on the Kursk […]. She said: 'If you betray your country you are a traitor and you will go to prison. But if your country betrays you, what can you do?' I think I have an answer to that: we can use our vote to get rid of those people who betrayed my son and other men like him. That's what I want the people of Sedgefield to do."
1