Given the task definition and input, reply with output. 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: What was the age of the oldest member (besides Stephanie) of the group representing Armenia in the Eurovision Song Contest 2015? Passage 1:Chemokine receptors are G protein-coupled receptors containing 7 transmembrane domains that are found predominantly on the surface of leukocytes, making it one of the rhodopsin-like receptors. Approximately 19 different chemokine receptors have been characterized to date, which share many common structural features; they are composed of about 350 amino acids that are divided into a short and acidic N-terminal end, seven helical transmembrane domains with three intracellular and three extracellular hydrophilic loops, and an intracellular C-terminus containing serine and threonine residues that act as phosphorylation sites during receptor regulation. The first two extracellular loops of chemokine receptors are linked together by disulfide bonding between two conserved cysteine residues. The N-terminal end of a chemokine receptor binds to chemokine(s) and is important for ligand specificity. G-proteins couple to the C-terminal end, which is important for receptor signaling following ligand binding. Although chemokine receptors share high amino acid identity in their primary sequences, they typically bind a limited number of ligands. Chemokine receptors are redundant in their function as more than one chemokine is able to bind to a single receptor.
Passage 2:A return to the Formula Three Euroseries beckoned for van Dam, with a 2009 campaign for Kolles & Heinz Union, the new team set up by Colin Kolles and Werner Heinz. However, the partnership was not to last, as after the rounds at Lausitz, van Dam parted company with the team. In four races, his best finish was eighteenth during the season-opening race at Hockenheim. Van Dam drove in the 24-hour endurance races at the Nurburgring and at Spa, before agreeing to drive the car of PSV Eindhoven in the Superleague Formula series. He replaced Dominick Muermans in the car, with the team lying eighteenth in the overall standings. However, he returned to the Euroseries, for the Barcelona rounds, rejoining his former team SG Formula.
Passage 3:In February 2015 she was announced as a member of the music group Genealogy (made up of singers from Armenia and the Armenian diaspora) that represented Armenia in the Eurovision Song Contest 2015. Stephanie Topalian represents the Asian continent in the formation whereas the Ethiopian Vahe Tilbian represents Africa, the American Tamar Kaprelian the American continent, the French Essai Altounian the European continent and the Australian Mary-Jean O'Doherty Basmadjian Oceania and Inga Arshakyan Armenia. The super group sang "Face the Shadow", the Armenian entry to the 2015 Eurovision Song Contest in Vienna, Austria. She became an Armenian citizen along with the other foreign members of Genealogy on 28 April 2015 after being given Armenian passports by President Serzh Sargsyan.
3