Kubla Khan or also known as "A Vision in a Dream: A Fragment by Samuel Taylor Coleridge is a detailed description of the palace of Xanadu. The poem starts off by describing the palace's setting which is known as the "pleasure dome". He intimately describes the said pleasure dome in the first stanza to quote: "In Xanadu did Kubla Khan /A stately pleasure-dome decree: /Where Alph, the sacred river, ran /Through caverns measureless to man /Down to a sunless sea. /So twice five miles of fertile ground /With walls and towers were girdled round; /And there were gardens bright with sinuous rills, /Where blossomed many an incense-bearing tree; /And here were forests ancient as the hills,/ Enfolding sunny spots of greenery.
Therefore, the answer is "D. gardens and forests".