The correct answer is disruptive mood dysregulation disorder.
As the name itself says, the behavior of these children is disruptive - they are likely to cause troubles and problems to those around them. Agnosia is a disorder characterized by the inability to process information, so it's wrong here. Dissociative identity disorder refers to multiple personalities disorder, which is not the case here. Anorexia is an eating disorder so it's also wrong here.
