Question: Eystein Haraldsson, was king of Norway from 1142 to 1157, "Øystein Haraldsson", is his name in which North Germanic language spoken mainly in Norway, where it is the official language?

Context paragraphs:
Ragna Nikolasdatter: Ragna Nikolasdottir (fl.  1140s – 1161) was a medieval Norwegian queen consort of King Eystein II of Norway ("Øystein Haraldsson").

Swedish language: Swedish (   ] ) is a North Germanic language, spoken natively by more than 9 million people predominantly in Sweden (as sole official language) and parts of Finland, where it has equal legal standing with Finnish.  It is largely mutually intelligible with Norwegian and Danish.  Swedish is a descendant of Old Norse, the common language of the Germanic peoples living in Scandinavia during the Viking Era.  It is currently the largest of the North Germanic languages by number of speakers.

Bengali language: Bengali ( ), also known by its endonym Bangla ( ; বাংলা ] ), is an Indo-Aryan language spoken in the Indian Subcontinent.  It is the national and official language of the People's Republic of Bangladesh, and the official language of some eastern and north-eastern states of the Republic of India, including West Bengal, Tripura, Assam (Barak Valley) and Andaman and Nicobar Islands.  It is also one of the 22 scheduled languages of India.  With 205 million speakers, Bengali is the seventh most spoken native language in the world by population.  Dictionaries from the early 20th century attributed slightly more than half of the Bengali vocabulary to native words (i.e., naturally modified Sanskrit words, corrupted forms of Sanskrit words, and loanwords from non-Indo-European languages), about 30 percent to unmodified Sanskrit words, and the remainder to foreign words.  Dominant in the last group was Persian, which was also the source of some grammatical forms.  More recent studies suggest that the use of native and foreign words has been increasing, mainly because of the preference of Bengali speakers for the colloquial style.  Today, Bengali is the primary language spoken in Bangladesh and the second most widely spoken language in India.

Sigurd II of Norway: Sigurd II Haraldsson (or Sigurd Munn) (Old Norse: Sigurðr Haraldsson) (1133–1155) was king of Norway from 1136 to 1155.  He was son of Harald Gille, king of Norway and his mistress Tora Guttormsdotter ("Þóra Guthormsdóttir").  He served as co-ruler with his half-brothers, Inge Haraldsson and Eystein Haraldsson.  His epithet Munn means "the Mouth" in Old Norse.  He was killed in the power-struggle against his brother, Inge, in an early stage of the civil war era in Norway.

German language: German ("Deutsch" ] ) is a West Germanic language that is mainly spoken in Central Europe.  It is the most widely spoken and (co-) official language in Germany, Austria, Switzerland, South Tyrol (Italy), the German-speaking Community of Belgium, and Liechtenstein.  It is also one of the three official languages of Luxembourg.  The languages which are most similar to German are the other members of the West Germanic language branch: Afrikaans, Dutch, English, the Frisian languages, Low German/Low Saxon, Luxembourgish, and Yiddish.  German is the second most widely spoken Germanic language, after English.

Norwegian language: Norwegian (norsk) is a North Germanic language spoken mainly in Norway, where it is the official language.  Along with Swedish and Danish, Norwegian forms a dialect continuum of more or less mutually intelligible local and regional variants.

Proto-Norse language: Proto-Norse (also called Proto-Scandinavian, Primitive Norse, Proto-Nordic, Ancient Nordic, Ancient Scandinavian, Old Nordic, Old Scandinavian, Proto-North Germanic, North Proto-Germanic or Common Scandinavian) was an Indo-European language spoken in Scandinavia that is thought to have evolved as a northern dialect of Proto-Germanic in the first centuries CE.  It is the earliest stage of a characteristically North Germanic language, and the language attested in the oldest Scandinavian Elder Futhark inscriptions, spoken around from the 2nd to 8th centuries (corresponding to the late Roman Iron Age and the Germanic Iron Age).  It evolved into the dialects of Old Norse at the beginning of the Viking Age in about 800, which later themselves evolved into modern North Germanic languages.

Eystein II of Norway: Eystein Haraldsson (Old Norse: "Eysteinn Haraldsson", Norwegian: "Øystein Haraldsson"); c.1125–1157) was king of Norway from 1142 to 1157.  He ruled as co-ruler with his brothers, Inge Haraldsson and Sigurd Munn.  He was killed in the power-struggle against his brother, Inge, in an early stage of the civil war era in Norway.

Assamese language: Assamese ( ) or Asamiya (Assamese: অসমীয়া "Ôxômiya ") is an Eastern Indo-Aryan language spoken mainly in the Indian state of Assam, where it is an official language.  It is the easternmost Indo-Aryan language and by extension the easternmost indigenous Indo-European language; it is spoken by over 15 million native speakers, and serves as a "lingua franca" in the region.  It is also spoken in parts of Arunachal Pradesh and other northeast Indian states.  Nagamese, an Assamese-based Creole language is widely used in Nagaland and parts of Assam.  Nefamese is an Assamese-based pidgin used in Arunachal Pradesh.  Small pockets of Assamese speakers can be found in Bangladesh.  The Indo-Aryan dialects of North Bengal and northwest Bangladesh are linguistically closer to Assamese, have cultural and literary affinities with Bengali.  In the past, it was the court language of the Ahom kingdom from the 17th century.

Danish language: Danish ("dansk" ] ; "dansk sprog", ] ) is a North Germanic language spoken by around six million people, principally in Denmark and in the region of Southern Schleswig in northern Germany, where it has minority language status.  There are also minor Danish-speaking communities in Norway, Sweden, Spain, the United States, Canada, Brazil and Argentina.  Due to immigration and language shift in urban areas, around 15–20% of the population of Greenland speak Danish as their home language.

Supporting paragraphs: Eystein II of Norway Norwegian language
Answer: Norwegian