Final answer:
The nurse should determine if the baby is breastfeeding, when the baby last received antibiotics, and how long the mother has been caring for the baby.
The correct options are 2, 3 and 4.
Step-by-step explanation:
The nurse should determine if the baby is breastfeeding, as this is a potential mode of HIV transmission from the mother to the child. HIV can be transmitted through breast milk, so it is important for the nurse to understand if the baby is being breastfed.
In addition, the nurse should also determine when the baby last received antibiotics, as a weakened immune system can make the baby more susceptible to opportunistic infections.
Finally, the nurse should also determine how long the mother has been caring for the baby, as this can provide insights into the potential duration of exposure to the HIV virus.