B. Louis' accident ended up improving the lives of blind people everywhere.
Explanation:
The "accident" being referred to here is how Louis Braille became blind. As a young boy he slipped into his father's workshop and used a tool wrong which pierced his eye and caused infection, rendering him blind.
This caused him to be unable to read normally, which is why is why he had to consort to reading the raised bumps on a page, and eventually developing the Braille system which improved the lives of blind people everywhere.
