The answer is A. The strongest effect on his literacy is the light it casts on the world he already knows.
Explanation:
In this passage from "Learning to Read and Write" Douglass tells his feelings and emotions as he learned how to read about this he suggests " I would at times feel that learning to read had been a curse rather than a blessing" because according to him, by reading he had realized how horrible and difficult his situation as a slave was. Also, due to this, he even envies those slaves that do not know how to read as he states "I preferred the condition of the meanest reptile to my own".
These ideas show literacy had a great effect on Douglass especially as it opened his eyes or cast light on the world, therefore the statement that bests the statement that is correct about the effect point of view of the author about this experience is "The strongest effect on his literacy is the light it casts on the world he already knows".
