Final answer:
The LPN with 20 years of experience should be assigned to the postpartum client with breastfeeding concerns, as they are skilled in providing care and education in this area.
Step-by-step explanation:
The client that the Certified Nurse (CN) should assign to the LPN with 20 years' experience is likely (a) The postpartum client with breastfeeding concerns. This is because LPNs, especially those with extensive experience, are well-equipped to handle postpartum care and can provide the necessary support and education regarding breastfeeding techniques and troubleshooting common issues like latch problems or milk supply concerns.
Clients (b) The newborn with jaundice, (c) The toddler with a fever, and (d) The adolescent with a broken arm, while within the scope of practice for an LPN, may require more immediate or complex medical interventions or evaluations that could be more appropriate for an RN or other advanced healthcare professional depending on the healthcare setting policies and the severity of the situation.