Where is the world's largest underground walkway?

Where is the world`s largest underground walkway?

Here is the question :

WHERE IS THE WORLD’S LARGEST UNDERGROUND WALKWAY?

Here is the option for the question :

Toronto
Shanghai
Hong Kong
Boston

The Answer:

And, the answer for the the question is :

Toronto

Explanation:

[STC001993] Do you long for an underground passageway where you can practice your cartwheels? According to Guinness World Records, the PATH complex in Toronto is the largest underground shopping complex as well as the largest underground walkway in the world. PATH is located in the city of Toronto. With its 19 miles of shopping arcades and 4 million square feet of retail space, you’re bound to find what you’re looking for in one of the mall’s 1,200 shops. Just enter the underground path through one of more than 50 office buildings, department stores, hotels, subway stations, or parking garages.