D minor.  Both use primarily the D minor pentatonic scale in various fretboard patterns on that whole tune.  They will occasionally add notes from D minor diatonic natural minor.  But the vast majority of the playing in from D minor pentatonic.

The tutorial I linked explains how you get from diatonic natural major or minor to pentatonic major or minor.  The pentatonic scales are just simplified subsets of the diatonic scales.