The correct option is C To not be able or willing to reflect on his past
In the context of the poem, the word 'opaque' is clearly signifying how he has been unable to learn from his mistakes and see where he went wrong; he uses the word opaque as something that is opaque doesn't let the light through; symbolic of how he couldn't see the lessons in his mistakes. Since Option C) is the closest in meaning to the above, it is the clear answer.