Final answer:
The nurse should reassure the mother and emphasize the importance of love and support for the baby.
Step-by-step explanation:
The best response by the nurse in this situation would be option a) "It's normal to feel overwhelmed, but your baby needs your love and support."
By acknowledging the client's worries and offering reassurance, the nurse can help alleviate the mother's concerns. It is important to emphasize the importance of the parents' love and support for the baby, as this will help create a nurturing environment for the child with Down syndrome.