The blood glucose level is commonly expressed as

1. The question asks for the common unit used to express blood glucose level. 2. In medical and clinical settings, blood glucose concentration is most commonly expressed in milligram per decilitre (mg/dL) (B), particularly in countries like the United States and India. 3. Another common unit used internationally, especially in Europe and Canada, is millimoles per litre (mmol/L). 4. Units like mm of Hg (A) measure pressure, parts per million (C) is used for trace concentrations, and grams per litre (D) represents a much larger concentration unit than typically used for blood glucose.