阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
An American woman has been held by authorities in China for the past six months accused of stealing state secrets. Mrs Phan-Gillis, a naturalised American born in Vietnam, was detained in March, during a trade visit to promote the Texan city of Houston. Sandy Phan-Gillis's husband Jeff Gillis says she is now being moved to a more secure facility.
China's Foreign Ministry spokesman Hong Lei said on Tuesday that Mrs. Phan-Gillis was "suspected of carrying out activities endangering national security, and is currently being investigated by relevant departments"."We hope that the outside world will respect China's handling of this case according to law," he added.
Mrs Phan-Gillis was president of the Houston Shenzhen Sister City Association and consulted for Chinese and US businesses. One of her colleages in the trip told the BBC "there was nothing out of the ordinary" about the trip but described the sequence of events as they left China as "bizarre". They had been travelling around China for about a week when the group went through immigration control at the border between Guangdong and Macau, in Zhuhai, on 19 March.
