A mother brings her 3-month-old infant to the clinic for evaluation of a cold. She tells the nurse that he has had "a runny nose for a week." When performing the physical assessment, the nurse notes that the child has nasal flaring and sternal and intercostal retractions. What should the nurse do next?

A. I: Cranial nerve I, the olfactory nerve, is responsible for the sense of smell and is not involved in visual acuity; it can be tested by asking the patient to identify familiar scents.

B. II: Cranial nerve II, the optic nerve, is responsible for transmitting visual information from the retina to the brain. It is directly involved in measuring visual acuity, as it enables the nurse to assess how well the patient can see and interpret visual stimuli; visual acuity is commonly tested using the Snellen chart.

C. IV: Cranial nerve IV, the trochlear nerve, controls the superior oblique muscle, which is responsible for downward and lateral eye movement. It can be assessed by having the patient follow an object in a downward diagonal direction.

D. III: Cranial nerve III, the oculomotor nerve, controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid. It is assessed by evaluating the patient's ability to follow objects in all directions and checking for pupil response to light and accommodation.

A. Insert a nasal tube into each nostril to ensure no blockage is present: Inserting a nasal tube is an invasive procedure that is not necessary for assessing nostril patency. This method can cause discomfort and does not provide a simple or effective assessment of airflow through the nostrils.

B. Refer patient to a nasal specialist to ensure there is not any blockage in the nasal cavity: Referral to a specialist is unnecessary for a basic assessment of nostril patency. The nurse can perform a simple, non-invasive test before considering a referral for further evaluation.

C. Press each nostril shut and have the patient sniff to ensure air passage through each nostril: This method effectively assesses nostril patency. By occluding one nostril at a time, the nurse can evaluate airflow and determine if there is any blockage or obstruction in the nasal passages. It is a quick and straightforward assessment technique.

D. Have the patient blow their nose into a tissue forcefully: Asking the patient to blow their nose can provide information about mucus presence or drainage but does not specifically assess nostril patency. This action may also cause discomfort and is not the best initial assessment for airflow through the nostrils.