The correct answer is option 1: New York Stock Exchange. In October 2012, the New York Stock Exchange was closed for two continuous days due to the devastating effects of hurricane Sandy. Hurricane Sandy was a powerful storm that affected the Northeastern United States, including New York City where the New York Stock Exchange is located.

Option 2, the Toronto Stock Exchange, is incorrect as it is located in Canada and was not affected by hurricane Sandy.

Option 3, the National Stock Exchange of Australia, is also incorrect as it is located in Australia and was not affected by hurricane Sandy.

Option 4, the London Stock Exchange, is incorrect as it is located in London, England and was not affected by hurricane Sandy.

Therefore, the correct answer is option 1: New York Stock Exchange.