Did Britain make the right decision in ceding Hong Kong Island & Kowloon to China?

Instead of just returning the New Territories? Apparantly it was a 'a cause of controversy in Britain at the time: some were surprised that the right wing Prime Minister Margaret Thatcher would agree to such an arrangement with the Communist government of China represented by Deng Xiaoping.

 

Please note that there was no option. The Territories were leased to the United Kingdom for a fixed period of time. The lease ran out. All Thatcher did was try and negotiate the best possible deal for the people, which is all she was capable of doing.