This year is the second year Sina and his brother have lived in Wuhan. After the coronavirus outbreak, the Iranian government dispatched charter flights to Wuhan to repatriate nationals. Sina's brother decided to go back to Iran and wanted Sina to go with him, but Sina's choice was to stay. Sina said he would not leave Wuhan at this ____________ moment.今年是Sina和弟弟在武汉的第二年。疫情发生后，伊朗政府派了专机接本国居民回国，Sina的弟弟决定回伊朗，希望Sina跟他一起回去。但是，Sina决定留下来。Sina说不想在这样的艰难时刻离开武汉。

A. difficult
B. easy