Answer:
The correct answer is b.a few days after birth
Explanation:
It was found in a research that only 1 day old infant is able to differentiate between her mother's milk odor and another women's milk odor to which he is unfamiliar.
It was also found that after 4 days an infant can differentiate between the milk of his own mother's breast from the milk of other woman's breast if the infant have skin to skin contact with his mother while breast feeding.
So infants can recognize the olfactory molecules which is unique in every mother and can tell the difference between their own mother's milk scent and another woman's milk scent.
