B1A4 (비원에이포) is a 5-member South Korean boy group under WM Entertainment. Group name stands for member's blood type and it's acronym for "Be The One, All For One."
Members are: Jinyoung (A blood type), Sandeul (A blood type), Gongchan (A blood type), CNU (A blood type), Baro (B blood type).
They released their first mini-album "Let's Fly" on April 21, 2011. WM Entertainment began revealing information about their new boy group on April 17th by showing one member a day.

Read more about B1A4 on Last.fm.