I believe the right answer is most likely the first option: A) Your face is as white as a lily.
This line was taken from the third stanza of the poem "La Belle Dame Sans Merci", by John Keats. The full stanza is as follows:
I see a lily on thy brow,
With anguish moist and fever-dew,
And on thy cheek a fading rose
Fast withereth too.
In the beginning of the poem, the speaker is asking a knight what happened to him, why he looks so sad and distressed. His face is pale and moist, like a lily. From the fourth stanza on, the knight tells his tale. He met a fairy in the woods and was seduced by her. In the end, however, he is imprisoned by the fairy and condemned to a sad fate.
And this is why I sojourn here,
Alone and palely loitering,
Though the sedge is withered from the lake,
And no birds sing.
