Q: Fact 1: Head hair is especially important in preventing heat loss from the body. Fact 2: Although hair is created by living follicles in the scalp, it's dead. Given the two facts above, what in the scalp is especially important in preventing heat loss from the body?

Select from:
[a]. cat hair;
[b]. a cuticle;
[c]. lint;
[d]. sweating;
[e]. dog hair;
[f]. living follicles;
[g]. staying warm;
[h]. looseness;
A:
[f].