Disney + Hans Christian Anderson
The Little Mermaid, and Little Match Girl are based on the source materials of the same names. Frozen is loosely based on The Snow Queen, and Fantasia 2000 features Piano Concerto No.2 which tells the story of The Steadfast Tin Soldier, based on the Hans Christian Anderson story of the same name.
Also worth noting, none of the adaptations take place in Denmark, their country of origin (except maybe the Piano Concerto No.2). The Little Mermaid takes place in Central America, The Little Match Girl takes place in Russia, and Frozen takes place in Norway.