What describes Lanugo hair?

Lanugo hair is a type of fine, soft hair that typically covers the bodies of fetuses during development in the womb and can also be present on infants after birth, particularly preterm infants. This hair serves as a protective layer, helping to regulate body temperature and protect the skin of the fetus. It is usually shed before or shortly after birth, making it a temporary form of body hair.

In contrast, the other types of hair mentioned in the options refer to different stages or characteristics of hair that are not related to fetuses or infants. Hair that develops after puberty relates to terminal hair, which is thicker and coarser. Fine hair that falls out easily can refer to vellus hair, which is distinct from lanugo. Thick hair associated with hormonal changes typically refers to terminal hair that may increase in response to hormonal fluctuations during puberty or hormonal conditions, further distinguishing it from the fine, soft characteristics of lanugo.