Which example of figurative language from Scene 5 of Macbeth best supports a developing theme about loyalty and betrayal?

A.
"When I burned in desire to question them further, they made themselves air"
B.
"Come, thick night, And pall thee in the dunnest smoke of hell"
C.
"yet I do fear thy nature; It is too full o' the milk of human kindness"
D.
"look like the innocent flower, But be the serpent under't."