In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

What is beneficial to London's economy?, Context: London is one of the leading tourist destinations in the world and in 2015 was ranked as the most visited city in the world with over 65 million visits. It is also the top city in the world by visitor cross-border spending, estimated at US$20.23 billion in 2015 Tourism is one of London's prime industries, employing the equivalent of 350,000 full-time workers in 2003, and the city accounts for 54% of all inbound visitor spend in UK. As of 2016 London is rated as the world top ranked city destination by TripAdvisor users.
Tourism

What did NBC delay for the west coast primetime?, Context: CBC's sports coverage has also attained high viewership in border markets, including its coverage of the NHL's Stanley Cup Playoffs, which was generally considered to be more complete and consistent than coverage by other networks such as NBC. Its coverage of the Olympic Games also found a significant audience in border regions, primarily due to the fact that CBC aired more events live than NBC's coverage, which had been criticized in recent years for tape delaying events to air in primetime, even if the event is being held in a market in the Pacific Time Zone during primetime hours on the East (where it would still be delayed for West coast primetime).
Olympic Games

Who did Ms. Symonds marry?, Context: Alexander Bell was born in Edinburgh, Scotland, on March 3, 1847. The family home was at 16 South Charlotte Street, and has a stone inscription marking it as Alexander Graham Bell's birthplace. He had two brothers: Melville James Bell (1845–70) and Edward Charles Bell (1848–67), both of whom would die of tuberculosis. His father was Professor Alexander Melville Bell, a phonetician, and his mother was Eliza Grace (née Symonds). Born as just "Alexander Bell", at age 10 he made a plea to his father to have a middle name like his two brothers.[N 6] For his 11th birthday, his father acquiesced and allowed him to adopt the name "Graham", chosen out of respect for Alexander Graham, a Canadian being treated by his father who had become a family friend. To close relatives and friends he remained "Aleck".

Alexander Melville Bell