How are progression and variation similar? a.) both state that changes in a routine are necessary for consistent gains. b.) both state that using a repetitive routine is necessary for best gains. c.) both represent major components of the fitt principle. d.) both are primarily used as injury-prevention methods.

“an abused child's thoughts occasionally drift to other, less anxiety-arousing topics; this anxiety reduction thus serves to strengthen 'other' thoughts, while weakening the thoughts about abuse.” a psychologist with which theoretical background would be most likely to offer this quotation as an explanation for the development of dissociative disorders?