The nurse is collecting a heel-stick blood specimen for a neonatal screen, which includes thyroxine (T4) and thyroid- stimulating hormone (TSH) levels, prior to discharging a 2-day-old patient. When the parents ask why these tests are being conducted, which explanation should the nurse provide?

This is a routine blood test required by law to screen for metabolic deficiencies.

Dosages for thyroid replacement therapy will be determined by this test.

This technique is used for early detection of intellectual disabilities.

These laboratory values will provide data to anticipate delays in growth and development.