I believe it is My Sisters which would be choice A
In the story "An Unlikely Heroine" by Elizabeth Kibler, Alisa also makes the happy outcome of the story possible by encouraging Teresa to stay on the team until the end of the season. Had Alisa not done that, Teresa would not have been able to step in to coach the team in the critical moment of the story.
The answer is B because "I have visited many cities including the following" indicates that there is going to be a list of cities. A colon is used to introduce a series of items or to separate two independent clauses; however the second sentence has to add on to the first.
