Select the best definition of Chronic obstructive pulmonary disease.

A. Persistent airflow limitation commonly related to smoking or noxious exposure. B. A chronic systemic autoimmune inflammatory arthritis typically affecting small joints symmetrically. C. Hyperglycaemia with ketonaemia and metabolic acidosis due to severe insulin deficiency. D. Neurological deficit caused by interruption of cerebral blood flow due to arterial occlusion.