I think its an Idiom. I don't see like or as. So no simile. I don't see he is something like a marshmallow. - No metaphor. I also don't see a non-human thing doing human things- the grass was dancing in the wind. My answer would be an idiom.
Hope this helps!
The coach brought the bag of team jerseys to the game
She is curious and independent
I’m not exactly 100% sure but I think it’s D
