Observe the given picture and choose correct set.

(a) A and B chains are connected by disulphide bonds 

(b) It is mature insulin 

(c) C peptide is not a part of it 

(d) It is a prohormone which needs to be processed inorder to become a functional hormone.

In mammals, including humans, insulin is synthesised as a pro-hormone (like a pro-enzyme, the pro-hormone also needs to be processed before it becomes a fully mature and functional hormone) which contains an extra stretch called the C peptide. This C peptide is not present in the mature insulin and is removed during maturation into insulin.