Which phrase from John Keats's "To Autumn" contributes to a mood of serene stillness?
A.
"sitting careless on a granary floor, /Thy hair soft-lifted by the winnowing wind"
B.
"Close bosom friend of the maturing sun"
C.
"in a wailful choir the small gnats mourn . . . borne aloft / Or sinking as the light wind lives or dies"
D.
"summer has o'er-brimmed their clammy cells"