4. All the above
Keep clothing clean and dry, Repair clothing as necessary and Wear clothing loose and layered are elements of the colder principle.
More information:
Colder Principle:
C- Keep your clothing CLEAN. Dirt can break down the fibers of your clothing.
O- Don't OVERHEAT. sweat can lessen the effectiveness of clothing.
L- Wear you clothes LOOSE and in LAYERS. Makes your system versatile.
D- Stay DRY.
E- EXAMINE you clothing. Look for worn or damaged areas of you clothing.
R- REPAIR any damage that is found.