What attempts have european imperial powers made in the 20th century to address the atrocities committed in colonies throughout the world? (select all that apply.) a. many european nations justify their actions by describing the internal improvements colonies went through to become civilized. b. many european nations have addressed their imperial actions by providing economic relief to their former colonies. c. many european nations supported a movement for self-determination within their colonies to end crimes against humanity. d. many european nations have chosen to deny the existence of atrocities by burning documentation and changing recorded history.