Small details on each one making huge difference. A and D are both look optimistic, but first one seems more active and initiative while prior one will give you a hearty hug and reassure things will be alright.
B and C are both felling neutral, but B is more like "oh well, I knew you could do this", while C is more strict and serious.
Can't pick a favorite because they're so different, but really like "metallic" hair on A and B.