What is the purpose of administering erythromycin ophthalmic ointment to a newborn?

Administering erythromycin ophthalmic ointment to a newborn is primarily done to provide protection against infections caused by Neisseria gonorrhoeae and Chlamydia trachomatis. These bacterial infections pose a significant risk to newborns as they can lead to severe conjunctivitis, which can result in serious complications, including blindness if untreated.

The ointment works as a prophylactic measure, particularly in infants born to mothers who are at risk of these infections or where screening has not been performed. The application of erythromycin is a standard practice in neonatal care to ensure that any bacteria that could be present in the birth canal do not cause harm to the infant's eyes after delivery.

Although the ointment can help in preventing conjunctivitis, the primary focus of its administration is the prevention of serious bacterial infections that can lead to conjunctivitis. Therefore, option B accurately represents the main purpose of administering erythromycin ophthalmic ointment to newborns.