Function of integumentary system: PROTECTION<span>- barrier against infectious, chemical, radioactive, and physical damage.
- keratin and junctions block bacteria, fungi, and blunt objects.
-macrophages identify foreign particles and activate immune response.</span>
Image result for Is work done when you carry a book across the room at a constant velocity
Work is not done when you carry an object forward. You may have learnt that carrying an object and moving horizontally at a constant velocity has no work done. The truth is, there is a slight amount of work done due to overcoming air resistance in the horizontal direction.
I would think it would be C
