Who among the following is exclusively associated with diary writing in English?

The correct option is Samuel Pepys.

Samuel Pepys (1633-1703) was an English administrator and Member of Parliament, who is most famous for keeping a detailed private diary from 1660 until 1669. His diary, first published in the 19th century, is one of the most important primary sources for the English Restoration period. It provides personal eyewitness accounts of major historical events, such as the Great Plague of London, the Second Dutch War, and the Great Fire of London.
Unlike the other individuals listed, Pepys's literary reputation is exclusively and almost entirely built upon his diary writing.

To understand why the other options are not exclusively associated with diary writing:
- Samuel Johnson (1709-1784) is a towering figure in English literature, famous for writing "A Dictionary of the English Language", essays, poetry, and biographies.
- Ben Jonson (1572-1637) was a renowned English playwright and poet, famous for plays like "Volpone" and "The Alchemist".
- Samuel Richardson (1689-1761) was a major English writer and printer, famous for his epistolary novels such as "Pamela" and "Clarissa".