Question: Age of Youth, is a South Korean television series stars include Ryu Hwa-young, a South Korean singer and actress, and is a former member of which South Korean girl group?
Sentence (from "Age of Youth"): It replaced "Mirror of the Witch" and aired on cable network JTBC on Fridays and Saturdays at 20:30 (KST) for 12 episodes from July 22 to August 27, 2016.
Relevant evidence: No