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 modern day country is the Principality of Serbia? Passage 1:Naitō Yorinao was the seventh son of Naitō Yoriyasu. However, as all of his elder brothers died in childhood he became daimyō in 1859 on the retirement of his father. In 1860, he established a han school, the Shintoku-kan (進徳館) in Takatō. He served as part of the escort to Princess Kazunomiya during her travel to Edo to marry the Shogun Tokugawa Iemochi in 1861. Following the Namamugi Incident of 1862, during which British subjects were killed by the retinue of Shimazu Hisamitsu, he was ordered by the shogunate to deploy his troops to Yokohama to increase security. These troops subsequently accompanied the Shogun's forces during the First Chōshū expedition. However, with the start of the Boshin War in 1868, Takatō quickly joined the imperial side against the Tokugawa. Even so, the domain was ordered to pay 2000 ryō to the new Meiji government to help pay for war expenses. Troops from Takatō participated in the Battle of Aizu under the command of Prince Saionji Kinmochi. Yorinao was appointed imperial governor of Takatō in 1869, serving until the abolition of the han system in 1871. He relocated to Tokyo at that time, and died in 1879. His grave is at the temple of Taizō-ji in Shinjuku, Tokyo.
 Passage 2:The modern Albanian-Serbian conflict has its roots in the expulsion of the Albanians in 1877-1878 from areas that became incorporated into the Principality of Serbia. Prior to the outbreak of the First Balkan War, the Albanian nation was fighting for a national state. At the end of 1912, the Porte recognised the autonomy of Albanian vilayet. These events for Albanian autonomy and Ottoman weakness were viewed at the time as directly threatening the Christian population of the region with extermination. The Balkan League (comprising Serbia, Montenegro, Greece and Bulgaria) jointly attacked the Ottoman Empire and during the next few months partitioned all Ottoman territory inhabited by Albanians. The Kingdom of Serbia and the Kingdom of Greece occupied most of the land of what is today Albania and other lands inhabited by Albanians on the Adriatic coast. Montenegro occupied a part of today's northern Albania around Shkodër. The Serbian army in the region viewed its role as protecting local Orthodox Christian communities and avenging the medieval battle of Kosovo, though it forced Catholic Albanians to convert to Orthodox Christianity.
 Passage 3:An ancient Amphictyony, probably the earliest centered on the cult of Demeter at Anthele or Anthela (Ἀνθήλη), which lay on the coast of Malis south of Thessaly. This was the locality of Thermopylae. Thus those living near the temple were called Amphictyones ("dwellers-round"). The immediate "dwellers-round", presumably the first members, were the small states Aeniania, Malis and Doris. Certainly Thessaly did have a share including the states of the Boeotian tribes who lived around Thessaly (perioikoi, "living around"). Boeotia and Phocis, the most remote of them may have joined during or after the "First Sacred War", which led to the defeat of the old priesthood, and to a new control of the prosperity of the oracle at Delphi. As a result of the war, the Anthelan body was known henceforth as the Delphic Amphictyony and became the official overseer and military defender of the Delphic cult. The name of Hellenes, which was originally the name of a Boeotian tribe in Thessalic Phthia, (Achaea Phthiotis) may likely be related to the members of that league and may have been broadened to refer to all Greeks when the myth of their patriarch Hellen was invented.

A:
2