Final answer:
The correct answer is B) Density. Hair density refers to the number of hair strands per square inch of the scalp. It is one of the genetically determined characteristics of hair, alongside color and texture.
Step-by-step explanation:
Hair density is the number of individual hair strands on 1 square inch of the scalp and is usually described as thin, medium, or thick. The correct answer to the question is B) Density. Hair density is a biological characteristic and is influenced by various factors, such as genetics and health. It is important not to confuse hair density with hair texture, which refers to the thickness or diameter of the individual hair strand, or with hair color, which depends on the melanin concentrations in the hair.
Hair growth occurs in three phases: anagen, catagen, and telogen. Genetics control visible characteristics of hair, including color, texture, and balding patterns. Hair fibers are composed of dead, keratin-filled cells, known as keratinocytes, which grow from hair follicles located in the dermis of the skin.