The nurse is on the mother baby unit teaching a new mother about changing the diaper of her 20-hour-old newborn. The mother is alarmed and asks why the stool looks black and sticky. Which response by the nurse would be most appropriate?

"You probably took iron during your pregnancy.”.

"Black stool is a sign of dehydration; has the lactation specialist been by to see you?"

"This is meconium stool, normal for a newborn.”.

"This is often associated with blood in the stool caused by a dairy allergy. Let's switch the baby's formula to the sensitive type.”. —