All of the Following Are Found in the Islets of Langerhans

All of the following are found in the islets of Langerhans EXCEPT

A) Cells that secrete a bicarbonate-rich alkaline fluid
B) Cells that secrete a hormone responsible for lowering blood glucose levels
C) Cells that secrete a hormone that results in the liver's breaking down glycogen
D) Cells that stimulate glycogen synthesis
E) Insulin-secreting cells