Ans. b. HypocalcemiaClinical findings of paresthesias, circumoral numbness and ECG showing tachycardia with ST-T changes are highly suggestive of hypocalcemia, which has been caused by extensive transfusion of citrated blood."Citrate, commonly used to anticoagulate blood components, chelates calcium and thereby inhibits the coagulation cascade. Hypocalcemia, manifested by circumoral numbness and/or tingling sensation of the fingers and toes, may result from multiple rapid transfusions."-H,"Transient hypocalcemia is seen with severe sepsis, burns, acute kidney injury, and extensive transfusions with citrated blood.