well, i chose "H" because of the order of skin to bone... So i assumed that "I" is probably ectoderm or simple connective tissue, couldn't really tell... I thought "G" was bone... While "H" was the muscle that usually surrounds bone typically in the limbs... I do admit that if it really is connective tissue, muscle, bone.. they all have a mesodermal origin.. but i defintelly know it cant be anything in the middle.
It looks more like an out branching of a forming limb or anything really. Its a tough question.. im not even sure if im right or not, but thats how i came 2 an answer