Though either of a. and b. could arguably be the correct answer, b seems the best option. For the Romantics, the wind was a symbol of creative power; one of their favorite metaphors for the poet was the aeolian lyre, a greek string instrument that was played by the wind. Here, the speaker begs the West Wind for inspiration that will transform him into a true poet, giving him the might of the forests and enabling him to sing.
