Final answer:
The most appropriate initial management for new-onset diabetic nephropathy involves lifestyle modifications and strict glycemic control to prevent further damage to the kidneys.
Step-by-step explanation:
The most appropriate next step in managing a person with new-onset diabetic nephropathy is A) Initiate lifestyle modifications and glycemic control. This progressive kidney disease caused by damage to the capillaries in the kidneys due to diabetes mellitus can often be managed initially with changes to diet and lifestyle, alongside strict blood sugar monitoring to prevent further damage. Interventions such as prescribing antihypertensive medications, implements low-sodium diets, and recommends cessation of smoking might also be indicated. Hemodialysis, kidney transplants, or high-protein diets are not typically first-line treatments for new-onset diabetic nephropathy unless the condition is advanced and accompanied by significant kidney failure.