Which one of the following became a part of China in 1997 following the principle of ‘one country, two systems’?

Originally designed for Taiwan, Beijing applied the “One Country, Two Systems” principle to Hong Kong on July 1, 1997 when sovereignty of the territory was passed from Britain to China.But “One Country, Two Systems,” which guarantees a degree of autonomy under Chinese supervision, isn’t applicable to Taiwan. The island has evolved into a self-ruled, hyper-democracy that enjoys de facto operational independence