I think the poem in question is actually "Ashes of Life" by Edna St. Vincent Millay.
If your question pertains to the subject of the poem as a whole, I believe the correct answer to your question is B. metaphor.
Metaphor means that a thing is not to be regarded in its literal sense, but as representative of something else. In this case, there are no ashes in the poem. But they are a metaphor of what's left of her life now that her beloved has abandoned her. We can also take this as an example of imagery, suggesting that she was burning with love, and now only ashes have remained.
However, if you take a closer look at some of the lines, such as "Love has gone and left me", it is a personification - giving human attributes to animals, abstract notions, or non-living things.