Which lines best depict a contemplative mood?

A) Around us shadows and the wind/Listened for what was never spoken.

B) The sun is bright,—the air is clear./The darting swallows soar and sing.

C) A pair of night-hawks windily sweep, or fall,/Booming, toward the trees.

D) All things rejoice in youth and love,/The fulness of their first delight!