The correct answer is “a wealthy businessman and a member of the Parliament.”
The Diary of Samuel Pepys is written from the point of view of a wealthy businessman and a member of the Parliament.
Samuel Pepys (1633-1703) was an English businessman, administrator of the navy, and member of the British Parliament who wrote his memories of every incident that happened in London. He wrote a detailed diary from 1660 to 1669 and included important incidents such as the Great Fire of London and the Great Plague of London. His diary was not published until the 19th century, and now represents a reliable source of information.
The other options of the question were, a) a child in the streets of plague-ravaged London, c) a plagued doctor seeking to a way to cure the disease, and d) a royal informant collecting information for the King.