Answer:
Collagen
Step-by-step explanation:
Elastin is a protein found in the the dermis at provides stretch, recoil and elasticity to your skin
Glycation is a process that ages your skin because of sugars
Keratin is a fibrous protein in the the pidermal layer at help make your skin and nails stronger
Collagen is a fibrous protein found in the reticular layer that is used to make connective tissue and is also the most abundant protein in your body.