A 72-year-old woman is brought to the ED 40 minutes after the sudden onset of expressive aphasia and left-sided weakness while dressing. Her family report she was previously living independently, managing all personal care, walking with a stick outdoors, and performing light household tasks. Her premorbid functional assessment confirms a modified Rankin Scale score of 1.

On arrival:

 RR 18/min, SpO₂ 98% RA, HR 90 bpm, BP 166/94 mmHg, glucose 6.0 mmol/L.

Neurology: left arm 2/5, left leg 3/5, severe expressive dysphasia.

Imaging:

CT head: no haemorrhage

CTA: left MCA occlusion

CT perfusion: small infarct core with large salvageable penumbra

  According to NICE NG128, which premorbid Rankin level is required for thrombectomy selection?