Read the following excerpt from Sonnet XLIII, "What lips my lips have kissed, and were, and why " by Edna St. Vincent Millay: What lips my lips have kissed, and where, and why,
I have forgotten, and what arms have lain
Under my head till morning; but the rain
Is full of ghosts tonight, that tap and sigh
Upon the glass and listen for reply,
And in my heart there stirs a quiet pain
For unremembered lads that not again
Will turn to me at midnight with a cry.

What aspect of this poem clearly marks it as a work of Modernism?

A. The author is influenced by the dark side of the human psyche.
B. The author expresses a sense of loss toward past lovers.
C. The author strays from a "happily ever after" treatment of romance.
D. The author focuses on physical pleasures over emotional pain.