A Patient with a Bleeding Ulcer Had an Elevated Heart

Multiple Choice

A patient with a bleeding ulcer had an elevated heart rate, but his blood pressure was very low and dropping. After the bleeding was stopped and a blood transfusion was given, blood pressure increased. Which of these statements are consistent with these observations?

A) Negative-feedback mechanisms are occasionally inadequate without medical intervention.
B) The transfusion interrupted a positive-feedback mechanism.
C) The transfusion interrupted a negative-feedback mechanism.
D) The transfusion was not necessary.
E) "Both negative-feedback mechanisms are occasionally inadequate without medical intervention" and "the transfusion interrupted a positive-feedback mechanism" are consistent.