Please answer the following question: Colorful hair speaks more about beauty. Now it becomes popular and people are dyeing their hair to make it different. Dyeing hair with natural products is good for health while dyeing with chemicals is harmful. Researches have found that dyeing hair with chemicals can make people have cancer. Lead is very harmful for the human body and it is used in most hair dyes. Since the base of hair is the scalp ,you may have allergic reaction . While dyeing your hair it is important to take some safety measures. You can follow them even when you are applying  dye on your hair at home. * It is better to apply hair dye for a few minutes. If you leave your hair with dye, longer than the necessary time,then you may get some skin problems. * Don't forget to wear gloves while applying dye on the hair. This will protect the skin of your hands. * After applying hair dye it is important to wash your hair with water. * Hair dyes are made of chemicals. If you mix different hair dyes ,there may be chemical reaction.  So, It is not a good idea to mix different hair dyes at the same time. * Finally all the bags of hair dyes carry the directions( ) Try to follow them very carefully. This will lower the chance of allergic reaction. What do most hair dyes contain? A) Iron B) Silk. C) Lead D) Gold
Answer:
C