What distinct odor is associated with burning wool fibers?

The distinct odor associated with burning wool fibers is reminiscent of burning hair. This similarity arises from the composition of both materials, as they are both made from proteins. Wool is made from keratin, which is also found in human hair. When these protein fibers burn, they produce a similar odor due to the breakdown of these proteins into compounds that emit a scent resembling charred hair.

The other odor options like burning plastic, rubber, or wood have very different chemical compositions and thus produce unique scents that do not correlate with the smell of burning wool. Burning plastic often has a sharp, chemical smell due to the synthetic materials, while wood releases a more earthy, organic scent when burned. Burning rubber tends to have a strong, acrid smell that is also distinct from that of protein fibers.