The right answer to this is C. Lye Relaxer. There are some people who are confused with lye relaxers and non-lye relaxers. A lye relaxer obviously comes with sodium hydroxide. The non-lye relaxer, on the other hand, has another ingredient which is calcium hydroxide. These two things are normally used for the hair.
The lye relaxer is said to work faster so it does not have to spend too much time on your hair. If you leave it too long, you may end up with an irritated scalp. A non-lye relaxer will work slower but it will not be too harmful to your scalp. It will be up to you which one you should pick.