One possible theme could be “how a person is affected by growing older”. Shakespeare compares old age to the seasonal shift. The narrator also describes how aging is harsh and ultimately comes to see its inevitability. Hope this helps!
I think it is D
Hope my answer help
The clause <em>when we can rest </em>is a subordinate/dependent clause, meaning that it cannot stand on its own - it has to be a part of a larger, independent clause, as is the case here.
