Participants seeking therapy for anger management were randomly allocated to one of two group therapy conditions (each using a different type of therapy), or to private 1:1 therapy. Their baseline level of anger was measured before treatment, and again after 3 months of weekly therapy sessions. To test for differences in the effectiveness of each condition while minimizing other sources of variance, the researcher analyzed these data using ANCOVA. What is the covariate in this model? O A) The anger scores after therapy O B) The anger scores before therapy O C) The private 1:1 therapy group O D) The type of therapy received O E) The difference in anger scores following therapy