The quote is incomplete. It should read: "For language is arbitrarily produced by the imagination, and has relation to thoughts alone; but all other materials, instruments and conditions of art have relations among each other which limit and interpose between conception and expression. The former is as a mirror which reflects, the later as a cloud which enfeebles the light of which both are mediums of communication. Hence the fame of sculptors, painters and musicians...has never equaled that of poets..."
A Defence of Poetry- Percy Shelley
In my view the correct answer should be B: “and has relation to thoughts alone”.
The reason being that as Shelley explains later, he considers that language has a direct, unique and exclusive relation with thoughts. Logically, thoughts are a direct product of the imagination, whether they are spontaneous or a result of external stimuli, and if according to his logic language is intimately and exclusively related to them it follows that language comes from the imagination. For Shelley as a poet, because language comes directly from imagination without the mediation or interference of any kind, poetry is the purest form of art.
The large group is excited about the upcoming event.
