Milton was blind. There was very little he could do that didn't require his eyes.
So he's asking if God (or man) takes away the light, what labor can he do?
I didn't see the choices. Mine would be C, but it is hard to eliminate D. As a somewhat religious person, I cannot bring myself to think God is responsible for my illnesses. It is just my body breaking down. All of us have that affliction (our bodies do break down to the point of no repair).
I accept D as a natural event that all of us succumb to. It is not God's doing. It is just us running out of time. You may find this a very unsatisfactory reason for not choosing D, but it is the way I would answer the question.
I think C explains the line much better than does D.
Answer:
How does God expect him to work when he is blind?
Explanation:
In this stanza, Milton reflects on the fact that he is losing his vision. Milton thinks of how his talents have always been employed in matters that require him to see. Moreover, these talents have enabled him to produce work throughout his life. Milton wonders how he will cope with going blind so young. He asks whether God expects him to be able to work in any way when he cannot see.
