Which does not contain a run-on sentence? a. the southern cross is the most identifiable constellation in the southern hemisphere these stars are easily visible most any time of the year. b. the southern cross is the most identifiable constellation, these stars are easily visible most any time of the year in the southern hemisphere. c. the southern cross is the most identifiable constellation in the southern hemisphere, and these stars are easily visible most any time of the year. d. the southern cross is easily visible most any time of the year, these stars are the most identifiable constellation in the southern hemisphere.