Which of the following are the weather conditions in some cities in northern China on a winter day: (1) some cities have snowfall; (2) some cities have no snowfall; (3) Beijing and Handan have no snowfall. If only one of the three assertions is true, which of the following options must be true? ['Snowfall in Beijing, but not in Handan.', 'Snowfall in all these cities.', 'No snow in all of these cities.', 'None of the above options may be true.']