B, there is a label that "medium temperature ironing" means that these fiber materials such as wool and polyester are characterized by high temperature resistance; So b is correct.
C, wool will have the smell of burnt feathers after burning, and polyester will melt into black balls after burning. So c is correct.
D. polyester is an important synthetic fiber. Polyester has the best strength, good elasticity, good wear resistance, corrosion resistance, heat resistance and thermal stability in synthetic fiber fabrics. Adding polyester to the fabric can increase the strength, elasticity, wear resistance, corrosion resistance, heat resistance and thermal stability of the fabric. So d is correct.
So choose one