News of war is fast becoming a way of life. The moment one picks up a newspaper, one is bombarded with news of wars between different countries, directly or indirectly. It is obvious that the countries at war are enemies and hatred is a part of this enmity. However the success of humanity comes when we rise above this enmity and show our love towards the civilization as a whole. Dr Sadao did the same. He did whatever he could to save the life of a man whom he knew was a war- prisoner. The instant he saw the injured man, he was filled with concern. Ignoring the fact that he was the enemy of his country and he must have killed so many Japanese and might kill even more, if alive, he saved him.
A compound (A) with molecular formula $C_4H_9I$ which is a primary alkyl halide, reacts with alcoholic KOH to give compound (B). Compound (B) reacts with HI to give (C) which is an isomer of (A). When (A) reacts with Na metal in the presence of dry ether, it gives a compound (D), C8H18, which is different from the compound formed when n-butyl iodide reacts with sodium. Write the structures of A, (B), (C) and (D) when (A) reacts with alcoholic KOH.