Write a multi-choice question for the following article, with the given choices and answer: Article: Have you ever been to the following places? If not, try to find a chance to visit them. Fez, Morocco Fez, about 240 miles northeast from Marrakesh,a wonderful scene is taking root slowly. It started with immigrants building castles, and continues as hotels and restaurants. The biggest news is that the Hotel Sahrai is completed with a bar and 50 rooms, many overlooking a pool. Catskills, New York The region that welcomed Jewish families in the 50s,hippies in the 60s, and soon, casino gamblers . Many stylish B&Bs have opened. Among them are the Hotel Dylan in Woodstock, the Arnold House in Livingston Manor,with its bar and diminutive spa . So now is the time to enjoy fly-fishing, hiking and other peaceful experiences. Rotterdam, Netherlands The constantly unfolding city center in Rotterdam has become one amazing explosion of style, which surprised the tourists greatly. The latest attraction, and reason enough to visit, is the MVRDV-designed Markthal, an igloo -like horseshoe that houses 20 shops, nine restaurants, and 228 apartments. It also happens to be Holland' s largest artwork. Chengdu, China Famous for its 1,600 pandas, most of which still live in the wild, Chengdu has introduced a 72-hour no-visa policy that makes it easier for Americans to drop in on one of the city' s three major panda research facilities. But it' s worth sticking around longer to experience what' s doing in Chengdu, a city on the rise. One of the shiniest attractions is New Century Global Centre, the world' s largest building, complete with an artificial beach. Options: A It improved its quality of service. B It introduced a 72-hour no-visa policy. C It built the world' s largest building. D It completed a building with an artificial beach. Answer: B It introduced a 72-hour no-visa policy. Question:
What did Chengdu do to attract the American travelers?