The May 17th episode of 'Produce X 101' showed the center selection process for the first "X1-MA" performance. Lee Dong Wook announced, "The center of 'X1-MA' has been selected by votes from the 101 trainees and 'Nation's Producers.'"
The top 3 nominees are Son Dong Pyo, Kim Woo Suk, and Kim Si Hoon. The young trainee, Song Dong Pyo, is ultimately announced the first center.
Son Dong Pyo showed tears while fellow trainees congratulated him on winning the first center. You can watch the center selection in the clip above.