Correct Answer: (b) Keratin
Solution:Keratin is an extremely strong protein that is a major component in skin, hair, nails, hooves, horns and teeth. Keratin is a key structural protein found in various parts of the body, including hair, nails, and the outer layer of skin (epidermis). It helps to protect cells from damage and provides strength and resilience to these tissues. Hair is composed of keratin cells, which are produced in the hair follicle and undergo a process called keratinization. This process transforms the cells into tough, non-living keratin fibers that form the hair shaft.