Question: Which language usually romanizes as Dang a Chinese surname which itself is occasionally used to romanize Deng?
Context: Wei (魏, 韋, 衛, 尉, 隗) is a Chinese surname.  It was ranked the 122nd most common Chinese surname in 2006.  Wei (魏) is the name used for the Kingdom of Wei. Chinese honorifics are words and phrases that indicate social respect or deference in the spoken or written language.  Especially before the twentieth century, the language used among friends would be very different from that used among strangers such as merchants.  Although most Chinese honorifics have fallen out of street use since the end of Imperial China, they can still be understood, and indeed occasionally used, by most contemporary Chinese speakers.  This is partly attributable to the popularity of Chinese historical novels and television dramas, which often employ language from the classical periods.  In general, language referring to oneself exhibits self-deprecating humbleness, while language referring to others shows approval and respect.  Honorific language in Chinese was often achieved by using honorific alternatives, prefixing or suffixing a word with a polite complement, or simply by dropping casual-sounding words. Xia is the Mandarin pinyin romanization of the Chinese surname written 夏 in Chinese character.  It is romanized Hsia in Wade–Giles, and Ha in Cantonese.  Xia is the 154th surname in the Song dynasty classic text "Hundred Family Surnames".  As of 2008, it is the 66th most common Chinese surname, shared by 3.7 million people. Yan is a Chinese surname, it is the pinyin romanization for several Chinese characters such as "严 (嚴 )", "晏 (晏 )", "偃 (偃 )", "颜 (顏 )", "言 (言 )", "燕 (燕 )", "阎 (閻 )", "闫 (閆 )", "鄢 (鄢 )" in simplified (traditional) form.  Note that these characters are spelled as Yen in the Wade–Giles romanization system which was the prevalent one before the early 80s.  From such, individuals and institutions who have had to romanize their Chinese names prior to that time, such as when having their books translated or publishing manuscripts outside of China, used "Yen" instead of "Yan".  Such examples include Yenching University and the Harvard-Yenching Institute.  The Yan surname in Taiwan is mostly spelled as Yen since only until recently has the government approved the use of pinyin romanization of names.  The Cantonese romanization of these surnames is "Yim".  As such, most people from Hong Kong and Chinese diaspora that emigrated prior to 1949 from Guangdong use the name Yim.  On many occasions, "甄 (甄 )" in Cantonese is also romanized as Yan. Hau is a surname.  It may be a variant spelling of the Chinese surname Hao 郝, the Cantonese spelling of the Chinese surname Hou 侯, or a Danish surname. Pang () is a Chinese surname.  In Cantonese, it is spelled "Pong".  In Vietnamese, it is spelled "Bàng".  "Pang" is also the Cantonese romanization of another Chinese surname Peng (). Chee is a Chinese surname.  It may refer to the Min Nan/Hokkien pronunciation of the Chinese surname pronounced Xú (徐) in Mandarin.  Notable people with the surname include: Cài () is a Chinese surname that derives from the name of the ancient Cai state.  It is regionally more common in China's Fujian Province and in areas settled by ethnic Chinese from that province than in China as a whole.  The surname is the 34th most common surname in China, but the 9th most common in Taiwan, where it is usually romanized as Tsai based on Wade-Giles romanization of Standard Mandarin and the 8th most common in Singapore, where it is usually romanized as Chua, which is based on its Teochew and Hokkien pronunciation.  Koreans use Chinese-derived family names and in Korean, Cai is 채 in Hangul, Chae in Revised Romanization, It is also a common Cantonese name in Hong Kong where it is romanized as Choy, Choi or Tsoi.  In Macao and Malaysia, it is spelled as Choi, in Malaysia and the Philippines as Chua, in Thailand as Chuo (ฉั่ว).  Moreover, it is also romanized in Cambodia as either Chhay, Chhuor or Chhor among Chinese Cambodians and as Tjoa or Chua in Indonesia. Tang is a pinyin romanization of various Chinese surnames, including Táng (唐) and Tāng (湯/汤).  Tang is also occasionally used to romanize Deng (鄧/邓, Pinyin: Dèng) and Teng (滕, Pinyin: Téng), especially for persons of Hong Kong origin, based on Cantonese pronunciation. Tang ( , Chinese: 唐, mandarin Pinyin: "Táng"; Japanese: 唐/とう/から; Korean: 당/唐; Cantonese : Tong; old Chinese read Dang), is a Chinese surname.  The three languages also have the surname with the same character but different pronunciation/romanization.  In Korean, it is usually romanized also as Dang.  In Japanese, the surname is often romanized as To.  In Vietnamese, it is commonly written as Đường (the anglicized variation is Duong, not be confused with Vietnamese surname Dương which is also anglicized as Duong).  It is pronounced dhɑng in Middle Chinese, and lhāŋ in Old Chinese.
Answer: Korean