Which of the following are the three main types of hair?

The three main types of hair are indeed lanugo, vellus, and terminal. Understanding these categories is essential in the context of personal grooming and waxing.

Lanugo refers to the fine, soft hair that covers the body of a fetus in the womb, which usually falls out before birth. Vellus hair is the soft, fine hair found on most areas of the human body, often referred to as "peach fuzz." This type of hair is typically light in color and shorter in length. Terminal hair, on the other hand, is thicker, darker, and coarser in texture. It's the hair you find on the scalp, eyebrows, and areas that may undergo hormonal changes, such as the underarms and pubic region, particularly after puberty.

This classification is essential for professionals in the beauty industry, especially when deciding on the appropriate techniques for hair removal, as the different types of hair respond differently to waxing and other removal methods. The other options—referring to types based on texture or appearance—do not address the biological classification of hair types and therefore are not the correct answer.