I think this is correct:
A. If the Pirates and Reds sweep these series, the Pirates would be in first place and would lead the Reds by 4.5 games. They currently lead Reds by 3.5 and they would gain a game.
B. If the Reds sweep and the Pirates win three of five against the Cards, then the Cards would be in first place and would lead the Reds by 3 games. The Cards currently lead by 5 and would lose two to the Reds.