Hairs are mostly fibrous proteins and are composed of keratin, and also the main constituent of skin, nails, wool, woof, feathers etc.
Keratin is the essential fibrous protein which has a structural and protective functions in the epithelium.
That would be the Endoplasmic Reticulum my good friend hope this helped... :D
Answer:
A lipid is any of various organic compounds that are insoluble in water. They include fats, waxes, oils, hormones, and certain components of membranes and function as energy-storage molecules and chemical messengers.
Well, we can rule out diffusion and osmosis because these are passive processes, so we're left with A and C. I'd say A, because the energy is used in muscle contraction.