Afederally funded research study involving children 8 to 12 years old involves collecting a single voided urine sample to assess the frequency of asymptomatic proteinuria (higher amounts of protein in the urine without any signs or symptoms of illness or infection). your irb has determined that assent of children age 8 and older is required for the study. a 10-year-old firmly declined to participate in the study described above. what kind of the action should be taken by the investigator?