Final answer:
Elasticity is the correct answer to the question, indicating the amount of movement in a hair strand. It is the hair's ability to stretch and return to its original length without breaking.
Step-by-step explanation:
The correct answer to the question about the amount of movement in the hair strand is D) Elasticity. Elasticity refers to the ability of a hair strand to stretch and return to its original length without breaking. It varies from client to client and even within different areas of the same head of hair. In contrast, Texture refers to the thickness or diameter of the individual hair strand, Density is the number of hair strands per square inch on the scalp, and Porosity is the hair's ability to absorb moisture and product.
Focusing on the reference information provided, in a sound wave, the parameter of the medium that varies with every cycle is a) The density of the medium. This is because sound waves are pressure waves that cause particles in the medium to compress and rarefy, temporarily changing the medium's density with each vibration or cycle.