Question: When was the band of the extended play To Be One officially announced?
Sentence (from "1X1=1 (To Be One)"): 1X1=1 (To Be One) (also known as 1×1=1 or To Be One) is the debut extended play by South Korean boy group Wanna One, a project group created through the 2017 Mnet survival show, "Produce 101 Season 2", composed of eleven trainees from different entertainment companies that will promote for 18 months under YMC Entertainment.
Relevant evidence: Yes