In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

Example input: For four years we have waited expectantly for the pitter patter of tiny paws. Soon, that wait could finally be over. Tian Tian, the UK's only female giant panda, has conceived and could give birth to a cub as early as August. However Edinburgh Zoo, where the pandas live, have warned people 'not to get too excited' as the process is 'extremely complex'. Moreover, on the two previous occasions keepers inseminated Tian Tian - whose name means 'Sweetie' - she has failed to produce a panda cub. She was artificially inseminated again in March this year, but keepers at the zoo say implantation - when a fertilised egg attaches to the uterus - has not yet occurred.Tian Tian has conceived and could give birth to a cub as early as AugustShe has been inseminated twice before but so far failed to produce a cubTian Tian and Yang Guang arrived in 2011 from China to great fanfareOn loan at £600k a year, became first giant pandas to live in UK for 17 years 
 Questions:Under the terms of the agreement any cubs will return to _ at the age of two, the age at which they would normally leave their mother in the wild.
Example output: China
Example explanation: This is a good example. Based on the passage, any cubs will return to China at the age of two
Q: ISIS has threatened Twitter founder Jack Dorsey and his employees after the site removed accounts linked to the extremists. Twitter confirmed to Daily Mail Online that the company was working with authorities to verify the seriousness of the threat which claimed employees' necks are 'a target for the soldiers of the Caliphate'. The chilling warning, written in Arabic, featured a picture of Dorsey in a gun's cross-hairs and the Twitter logo. It was posted on Sunday on an anonymous site based in Poland which is used by programmers to share code. Dorsey, who is worth an estimated $2.5billion and lives in California, made no mention of the threat online on Sunday as he tweeted his 2.87million followers.Twitter confirmed to Daily Mail Online on Monday that the company was working with authorities to verify the seriousness of the threatThe threat, featuring a picture of Dorsey in a gun's cross-hairs and the Twitter logo, was posted on Sunday 
 Question:According to _'s rules: 'You may not publish or post direct, specific threats of violence against others.'
A:
Twitter