With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: In South Korea, April 5, Singmogil or Sikmogil (식목일), the Arbor Day, was a public holiday until 2005. The South Korean public still celebrate Singmogil by taking part in tree-planting activities because it is still an official holiday.
text_B: Do Koreans only plant trees because Singmogil is a holiday?
DON'T KNOW.