Based on this excerpt from "porphyria's lover” by robert browning, what does the setting contribute to this poem?

the rain set early in to-night,
the sullen wind was soon awake,
it tore the elm-tops down for spite,
and did its worst to vex the lake:
i listened with heart fit to break.
when glided in porphyria; straight
she shut the cold out and the storm,
and kneeled and made the cheerless grate
blaze up, and all the cottage warm;
which done, she rose, and from her form
withdrew the dripping cloak and shawl,
and laid her soiled gloves by, untied
her hat and let the damp hair fall,
and, last, she sat down by my side
and called me. when no voice replied,
she put my arm about her waist,
and made her smooth white shoulder bare,
and all her yellow hair displaced,
and, stooping, made my cheek lie there,
and spread, o'er all, her yellow hair,
murmuring how she loved me—she
too weak, for all her heart's endeavour,
to set its struggling passion free
from pride, and vainer ties dissever,
and give herself to me for ever.
but passion sometimes would prevail,
nor could to-night's gay feast restrain
a sudden thought of one so pale
for love of her, and all in vain:

a. the storm enhances the mysterious quality of porphyria and her appearance.
b. the power of the storm underscores porphyria's power.
c. the wildness of the storm contrasts with porphyria's conventionality.
d. the destructive nature of the poem echoes porphyria's limitless passion.