A 9-year-old boy is brought to the PMHNP by his mother after six weeks of persistent school refusal. He cries every morning before school, complains of stomachaches and headaches that resolve on weekends, and has begun sleeping in his parents' bed. His teacher reports he was previously an average student with a few close friends but has become increasingly withdrawn since the start of the school year. There is no history of bullying, academic failure, or learning disability. Family history is notable for panic disorder in the mother and generalized anxiety disorder in the maternal grandmother. A medical workup for gastrointestinal and neurological causes was negative. The PMHNP is developing an evidence-based treatment plan. Which of the following intervention strategies is most consistent with current evidence for school refusal associated with anxiety in this age group?