you can talk to a GP or a dietitian.
No, these fumes will not cause cancer nor will damage your hair. The only thing truly damaging your hair is blow drying it every day because it can dry it out, so try not to do that! It is not that bad though.
I would choose C, because a first degree burn is like you burned yourself on a pan and it kinda hurts, but a second degree burn would have slightly more pain, and a fourth degree burn would probably cause death.
So, I'd choose C if I were you, as it will have scarring, a lot of pain, and if you google pictures ( don't, it's really gross ) there's usually really bad blisters.
A. help keep joints flexible