A nurse is caring for a newborn diagnosed with a cleft lip. The nurse understands that the cause of the cleft lip is most often related to which of the following factors?

"It is caused primarily by a combination of genetic factors and maternal environmental exposures during early pregnancy, such as smoking, certain medications, D and Infections."

"A cleft lip is due to an abnormal autoimmune response."

"Intrauterine hypoxia causing tissue necrosis of the lip during the third trimester."

"Postnatal trauma to the upper lip during delivery."