The pancreas is made up of two parts $A$ and $B$. The part $A$ secretes insulin whereas part $B$ secretes pancreatic juice. $(a)$ Which part is functioning as an endocrine gland? Why? $(b)$ What is insulin and what effect does it have in the body? $(c)$ Name the disease which can be treated by giving insulin injection. $(d)$ What does pancreatic juice contain? Where does pancreatic juice go? $(e)$ Name the life process in which pancreatic juice is made use of.