Final answer:
John Milton was traumatized by his blindness, which significantly influenced his life and work, particularly seen in his sonnet 'On His Blindness'.
Step-by-step explanation:
The event that traumatized John Milton and impacted his perspective on life was d) His blindness. Milton's loss of sight was a profound personal tragedy that deeply affected his work and worldview. His blindness is often reflected in his later poetry, particularly in the sonnet 'On His Blindness,' where he grapples with his condition and his continuing desire to serve God. This loss forced Milton to dictate his works and may have contributed to the somber and reflective nature of his later pieces, such as 'Paradise Lost.'