Question: What subsidiary of the largest airline of the Republic of China (Taiwan) has a main hub at Taichung Airport?

Context:
History of British Airways
British Airways (BA) is the flag carrier airline of the United Kingdom.
 It is the largest airline in the UK based on fleet size, international flights and international destinations.
 British Airways was considered the largest UK airline by passenger numbers from its creation in 1974 until 2008, when it was displaced by low-cost rival EasyJet.
 Since its inception, British Airways has been centred at its main hub at London Heathrow Airport, with a second major hub at London Gatwick Airport.
Hawaiian Airlines
Hawaiian Airlines (Hawaiian: "" ) is the largest airline in Hawaii.
 It is the 8th largest commercial airline in the US, and is based in Honolulu, Hawaii.
 The airline operates its main hub at Honolulu International Airport and a secondary hub out of Kahului Airport on the island of Maui.
 Hawaiian Airlines operates flights to Asia, Hawaii, New Zealand, Australia and the United States Mainland.
 Hawaiian Airlines is owned by Hawaiian Holdings, Inc. of which Mark Dunkerley is the current President and Chief Executive Officer.
Taichung County
Taichung County was a county in central Taiwan, the Republic of China, that surrounded but did not include the former Taichung City.
 The county capital was Fengyuan.
 The name "Taichung" means "central Taiwan".
Jet Airways
Jet Airways (Hindi: जेट एयरवेज , "Jet Eyaravej") is a major Indian international airline based in Mumbai.
 In July 2017, it was the second largest airline in India after IndiGo with an 18.2% passenger market share.
 It operates over 300 flights daily to 68 destinations worldwide from its main hub at Chhatrapati Shivaji International Airport and secondary hubs at Amsterdam Airport Schiphol, Chennai International Airport, Indira Gandhi International Airport, Kempegowda International Airport and Netaji Subhas Chandra Bose International Airport.
Taichung International Airport
Taichung International Airport () (IATA: RMQ, ICAO: RCMQ) , previously known as Ching Chuan Kang Airport (), is an international airport located in Taichung City, Taiwan (ROC) for both commercial and military purposes.
 It is also the third international airport in Taiwan, with scheduled services to Mainland China, Japan, South Korea and Vietnam.
China Airlines
China Airlines (CAL) () () is the flag carrier and largest airline of the Republic of China (Taiwan).
 It is headquartered in Taoyuan International Airport and has 12,607 regular employees.
 China Airlines operates over 1,400 flights weekly to 118 airports in 115 cities (including codeshare) across Asia, Europe, North America and Oceania.
 The cargo division operates 91 pure freighter flights weekly.
 The carrier was, in 2013, the 29th and 10th largest airline in the world in terms of passenger revenue per kilometer (RPK) and freight RPK, respectively.
 China Airlines has three airline subsidiaries: Mandarin Airlines operates flights to domestic and low-demand regional destinations; China Airlines Cargo, a member of Skyteam Cargo, operates a fleet of freighter aircraft and manages its parent airline's cargo-hold capacity; Tigerair Taiwan is a low-cost carrier established by China Airlines and Singaporean airline group Tigerair Holdings and is wholly owned by China Airlines Group.
Blue Line (Taichung Metro)
The Taichung BRT Blue Line (Chinese: 臺中快捷巴士) was a Bus Rapid Transit (BRT) system located in Taichung which stretched from Taichung Station to Providence University on the main road, Taiwan Boulevard.
 The line was 17.1 km in length with 21 stations.
 It was the first BRT line in Taiwan.
 The line was converted to dedicated bus lane for conventional buses on July 8, 2015 and the BRT is no longer in operation.
Mandarin Airlines
Mandarin Airlines () is an airline based in Taipei, Taiwan, whose parent company is China Airlines.
 The Taiwanese carrier operates domestic and regional international flights, while its parent company focuses on international operations.
 Charter services are also operated by the company.
 Its other main hub is the Taichung Airport.
AirAsia
AirAsia Berhad () is a Malaysian low-cost airline headquartered near Kuala Lumpur, Malaysia.
 It is the largest airline in Malaysia by fleet size and destinations.
 AirAsia Group operates scheduled domestic and international flights to more than 165 destinations spanning 25 countries.
 Its main hub is klia2, the low-cost carrier terminal at Kuala Lumpur International Airport (KLIA) in Sepang, Selangor, Malaysia.
 Its affiliate airlines Thai AirAsia, Indonesia AirAsia, Philippines AirAsia, and AirAsia India have hubs in Don Mueang International Airport, Soekarno–Hatta International Airport, Ninoy Aquino International Airport, and Kempegowda International Airport respectively, while its sister airline, AirAsia X, focuses on long-haul routes.
 AirAsia's registered office is in Petaling Jaya, Selangor while its head office is at Kuala Lumpur International Airport.
2007 Baseball World Cup
The XXXVII International Baseball Federation (IBAF) Baseball World Cup was held in the Republic of China (Taiwan, competing under the name of Chinese Taipei) from November 6 through November 18, 2007.
 Four stadiums hosted.
 Taichung Intercontinental Baseball Stadium and Taichung Baseball Field in Taichung City, Tianmu Baseball Stadium in Taipei City and Sinjhuang City all played host to the tournament.
 Sixteen teams participated.
 At one time, Venezuela’s participation was in question due to possible sanctions to be considered by the International Baseball Federation in the wake of their refusal to grant visas to a youth team from Taichung to participate in the Youth World Baseball championships in August, 2007, but they were allowed to participate.
 China was originally scheduled to participate in Pool B, but dropped out and was replaced by Thailand, who placed fifth behind China at the Asian Games.

Answer: Mandarin Airlines