From Emperor to citizen, the speaker's attitude towards his childhood years was unsatisfied and unhappy.
He graved for change from a person who's life is less to complex to simplier one. He's childhood years was full of dreams that he wants to be a man with power like an emperor, but indeed like an ordinary citizen.
The correct answer would be B. It makes the sentence clear and concise.
The purpose of King’s letter is to cause negotiation to fight crisis.