A 28-year-old woman presents with irregular menses (4–5 cycles per year), hirsutism in a male-pattern distribution, and acne. On examination, she is overweight (BMI 29 kg/m²). Transvaginal ultrasound confirms polycystic ovaries (≥12 follicles per ovary). The pathophysiologic mechanism marked **A** in the diagram (Insulin Resistance / Hyperinsulinemia) drives hyperandrogenism in this patient primarily through which of the following mechanisms?