After Reading the Paragraph Below, Answer the Questions That Follow

After reading the paragraph below, answer the questions that follow.
Under normal conditions, blood sugar levels are controlled within a narrow range by negative feedback. Two hormones are involved in maintaining blood sugar levels at the set point (about 90 mg of glucose/100 mL of blood) . When blood sugar levels rise above the set point, the hormone insulin signals the liver to absorb the excess sugar. When blood sugar levels drop below the set point, the hormone glucagon signals the liver to release its stored glucose to the bloodstream. In juvenile onset diabetes, the body doesn't produce enough insulin and insulin supplements are required.
-Based on your understanding of homeostasis, for negative feedback control of blood glucose levels to function properly,

A) the control center for glucose must be somewhere in the digestive system.
B) there must be sensors that monitor blood glucose levels.
C) there must be several other hormones involved (in addition to insulin and glucagon) .
D) the body must prevent glucose levels from changing even slightly.