Reversibility Testing 12% 200mL FEV1 Post-BD

A 32-year-old male office worker with remote childhood asthma presents with 3 months of progressive dyspnea on exertion and nocturnal cough. Baseline spirometry (after appropriate SABA/LABA washout) shows FEV₁ 2.65 L (72% predicted), FVC 4.10 L, and FEV₁/FVC 0.65, with a concave scooped expiratory limb on flow-volume loop. Post-bronchodilator spirometry 10–15 minutes after salbutamol 400 mcg via spacer is performed. The loop marked **C** in the diagram shows FEV₁ 3.10 L (84% predicted) and FEV₁/FVC 0.71. Which of the following best describes the clinical significance of the change demonstrated in structure **C** according to ATS/ERS 2019 standardization criteria?