The answer is C. Who really knows?
My answer is D) The years gone by
The following is my reasoning:
This poem has a theme of losing a loved one and the process of aging and in the lines "Murmur, a little sadly, how Love fled / And paced upon the mountains overhead / and hid his face amid a crowd of stars." The narrator wrote this poem for his wife to read in her old age, assuming he wrote this for her before his own death (this statement is supported by the first stanza of the poem).
I believe that the line from "Helen Grey" which suggests that Helen has an unrealistic sense of herself is the last option - Stoop from your cold height, Helen Grey.
She is giving advice to herself that she should change because nobody will be there for her unless she does that.
