BTS has demonstrated enduring market power following its full-group comeback, raising expectations for a revival in the K-pop album market. The septet’s fifth LP, “Arirang,” which released Friday, has contributed to reaffirming BTS’ dominance. The album surpassed 4 million sales within just three days of its release, debuting at No. 1 on the Hanteo weekly album chart. In doing so, BTS quickly surpassed its own first-week sales record of 3.37 million copies for 2020 album “Map of the Soul: 7,” hi