Which statement most accurately describes Severe acute malnutrition?

A. A glucose-electrolyte solution that promotes intestinal sodium and water absorption. B. A condition identified by very low anthropometry, oedema or other accepted criteria and associated with high clinical risk. C. Invasive meningococcal infection that may cause rapidly progressive sepsis and purpura. D. An upper-airway viral illness characterised by barking cough and inspiratory stridor.