Complex sentence: In December 2015, MBK Entertainment announced Chaeyeon temporarily withdrawn from the group to join survival program "Produce 101", she auditioned and signed contracts with the show before DIA's official debut.
Split into simpler sentences: In December 2015, MBK Entertainment announced Chaeyeon has temporarily withdrawn from the group to join survival program "Produce 101". She auditioned and signed contracts with the show before DIA's official debut.