How Do Most Integral Membrane Proteins Interact with the Lipid

How do most integral membrane proteins interact with the lipid bilayer?

A) By covalent attachment to a glycosylphosphatidylinositol anchor.
B) Through covalently bound fatty acids.
C) By electrostatic interactions with the head groups of membrane lipids.
D) By a little piece of hydrophobic a helix that traverses the lipid bilayer.
E) By hydrogen bonds with the head groups of membrane lipids.