Final answer:
Neonatal conjunctivitis can occur within the first few days of life, depending on the specific pathogen causing the infection.
Step-by-step explanation:
The onset of neonatal conjunctivitis can occur within the first few days of life. Neonatal conjunctivitis is a condition where a newborn's eyes become inflamed and infected. It can be caused by exposure to pathogens during passage through the birth canal, particularly if the mother has certain sexually transmitted infections such as gonorrhea or chlamydia.
The onset of neonatal conjunctivitis is dependent on the specific pathogen causing the infection. For example, gonococcal ophthalmia neonatorum, caused by Neisseria gonorrhoeae, may develop within the first day of life. On the other hand, inclusion conjunctivitis, caused by Chlamydia trachomatis, may develop within the first few days. Therefore, the correct answer to your question would be option 1) Within 1st day of life.