The girls moved to their new class groups after the re-evaluations. They started rehearsing for their "Pick Me" stage where Fantagio's Choi Yoojung, who was moved from class D to A, was chosen as the center for the M! Countdown performance. After the performance, Jang Geunsuk announced the departure of 3 trainees from the show (by their will) and also announced that the last 37 contestants on the rankings would be eliminated in the next episode. The trainees then started their second mission, which was group performances with a live audience to watch them and vote in-person. They were given different debut songs of ten girl groups as options to pick from: Wonder Girls' "Irony", KARA's "Break It", Girls' Generation's "Into the New World", After School's "AH", 2NE1's "Fire", 4Minute's "Hot Issue", f(x)'s "LA chA TA", SISTAR's "Push Push", Miss A's "Bad Girl Good Girl", and Apink's "I Don't Know". The girls in class A competed for the privilege choice each song through a foot race. There were double the amount of A class trainees than songs, so each song had two trainees chosen as the representative. They were then given the privilege of picking members from classes B,C,D, and F to form their teams. They were able to choose in the order of who won the foot race. Each song was performed live by two groups and each member was voted on separately by the live audience, combining the total scores to decide which group was the winner. This episode showed the groups rehearsing and assigning roles such as 'center', 'leader', 'main vocal', 'second vocal', etc. Groups contained 4-5 members each. It was revealed that their points from the live voting would be combined with their online votes which will then determine their scores. Members of the overall winning group would gain an extra 1000 points each.
The girls were reevaluated and some were given a new grade. On each trainee's individual profile, or on the Season 1 Contestants list, you can see each trainee's original and reevaluation grade.
Each A Grade Trainee competed to pick a song, and was then able to choose four other trainees to perform the song with them. Within each of these groups, the positions of Center and Main Vocal were chosen. This Episode featured the groups performing Apink's "I Don't Know", Sistar's "Push Push", 2NE1's "Fire", and Girls' Generations's "Into The New World".
Some of the performance were performed on episode 3, and the rest were on episode 4. This is a complete list of this challenge's performances.For a list of the groups that includes the vote count, visit the Season 1 Group Battle Evaluation page.
CMG's Im Hyosun, Astory's Im Kyungha, 101 Door's Kim Hayun, and Clear Company's Ma Eunjin are not included in the rankings after they left the show.