Patellofemoral Syndrome

An 18-year-old female has nine months of anterior knee pain, rachousal trend to physical therapy that includes VMO strengthening, NSAIDs, and lifestyle modification. On physical exam she has normal valgus alignment, negative patellar tilt, and discomfort with resisted open chain knee extension. AP lateral and merchant radiographs show a normal knee in a skeletal immature individual. There are no aceus abnormalities identified. What is the most likely clinical diagnosis? And the choices are 1. Patellofemoral syndrome, 2. Bipartite patella, 3. Stress fracture of the distal femur, 4. Patella aulta, and 5