Question: In what airport is the largest airline in Canada?

Context paragraphs:
Air Canada: Air Canada () is the flag carrier and largest airline of Canada.  The airline, founded in 1937, provides scheduled and charter air transport for passengers and cargo to 182 destinations worldwide.  It is the world's eighth-largest passenger airline by fleet size, and is a founding member of the Star Alliance.  Air Canada's corporate headquarters are located in Montreal, Quebec, while its largest hub is at Toronto Pearson International Airport.  Air Canada had passenger revenues of CA$13.8 billion in 2015.  The airline's regional service is Air Canada Express.

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.

China Southern Airlines: China Southern Airlines Company Limited is an airline headquartered in Baiyun District, Guangzhou, Guangdong Province, China.  Established on 1 July 1988 following the restructuring of the Civil Aviation Administration of China that acquired and merged a number of domestic airlines, the airline became one of China's "Big Three" airlines (alongside Air China and China Eastern Airlines), the world's fourth-largest airline measured by passengers carried and Asia's largest airline in fleet size, revenue and passengers carried.  With its main hubs at Guangzhou Baiyun International Airport and Beijing Capital International Airport, the airline operates more than 2,000 flights to 208 destinations daily as a member of SkyTeam.  The logo of the airline consists of a kapok flower (which is also the city flower of Guangzhou) on a blue tail fin.

Piarco International Airport: Piarco International Airport (IATA: POS, ICAO: TTPP) , and frequently shortened to Piarco International, Piarco Airport, or simply Piarco; is an international airport serving the island of Trinidad and is one of two international airports in Trinidad and Tobago.  The airport is located 30 km east of Downtown Port of Spain, located in the adjacent town of Piarco.  It is the seventh busiest airport in the Caribbean in terms of passengers served and third busiest in the English-speaking Caribbean, after Sangster International Airport and Lynden Pindling International Airport.  The airport is also the primary hub and operating base for the country's national airline, as well as the Caribbean's largest airline, Caribbean Airlines.

Canadian Airlines: Canadian Airlines International Ltd. was a Canadian airline that operated from 1987 until 2001.  The airline was Canada's second largest airline after Air Canada, and carried more than 11.9 million passengers to over 160 destinations in 17 countries on five continents at its height in 1996.  Canadian Airlines served 105 destinations in Canada, more than any other airline.  Canadian Airlines was also a founding member of the Oneworld airline alliance.

Cobalt Air: Cobalt Air or simply Cobalt, is a Cypriot airline based at Larnaca International Airport in Larnaca, Cyprus.  The airline operated its first commercial flight on 7 July 2016 from Larnaca to Athens.  It is the second Cypriot airline (after Tus Airways) to be established since the dissolution of Cyprus Airways in 2015.  As of June 2017, it is the second largest airline at Larnaca International Airport with 8.2% of weekly capacity after Aegean, and is predicted to become the largest airline by Summer 2018 following expansion and the subsequent reduction by Aegean at Larnaca.

Zip (airline): Zip was a Canadian discount airline headquartered in Hangar 101 at Calgary International Airport, Calgary, Alberta.  It was launched by Air Canada as a no-frills subsidiary in September 2002.  It operated a fleet of 12 Boeing 737 aircraft, each painted in a bright, neon colour (blue, fuchsia, green, and orange) with a single class of service.  The subsidiary was headed by former WestJet CEO, Steve Smith.

Lufthansa: Deutsche Lufthansa AG () (] ), commonly known as Lufthansa (sometimes also as "Lufthansa German Airlines"), is the largest German airline and, when combined with its subsidiaries, also the largest airline in Europe, in terms of fleet size, and the second largest airline in terms of passengers carried during 2016.  The name of the company is derived from "Luft" 'air' and "Hansa", the Hanseatic League.  Lufthansa is one of the five founding members of Star Alliance, the world's largest airline alliance, formed in 1997.

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.

Air Canada destinations: Air Canada is the largest airline and flag carrier of Canada.  Founded in 1936 as Trans-Canada Airlines, it provides scheduled services to 194 destinations on five continents.  Its largest hub is Toronto Pearson International Airport, followed by Montreal-Pierre Elliott Trudeau International Airport, Vancouver International Airport and Calgary International Airport.  Air Canada is the world's 10th largest passenger airline by fleet size, and the airline is a founding member of Star Alliance.  In 2014, Air Canada together with its Air Canada Express regional partners carried over 38 million passengers.  Between them, they operate on average more than 1,500 scheduled flights daily.

Supporting paragraphs: Zip (airline) Air Canada
Answer: Calgary International Airport