A

The presentation is a classic nephrotic syndrome (edema, 3+ proteinuria, hypo-albuminemia) with normal renal function and, importantly, no hematuria or cellular casts—findings that point to minimal-change disease, the prototypical cause of selective, bland nephrotic urine sediment, especially in children [Abellada, 2024, PMID 39163011; Chowdhury, 2018, PMID 29682437].