Q: Fact 1: Hair is a fiber that is found only in mammals. Fact 2: Animals can be classified into mammals, reptiles, birds. Given the two facts above, what is a fiber that is not found in reptiles or birds?

Available choices:
A). Tail;
B). muscle;
C). feathers;
D). sugar;
E). down;
F). hair;
G). Fat;
H). scales;
The answer is:
F).