The graph represents a person's blood sugar level across eight hours. No exercise was done during this period. Which statement accounts for the shape of the graph between $X$ and $Y$?
- AThe pancreas produces glucagon which causes excess sugar in the blood to be converted to glycogen.
- BThe liver produces insulin which causes excess sugar in the blood to be converted to glycogen.
- CThe pancreas produces insulin which causes excess sugar in the blood to be converted to glycogen.
- DThe liver produces glycogen which causes excess sugar in the blood to be converted to glucagon.