I believe it is A. Because it’s talking about how the salt is a danger and letter A talks about the danger of it.
Smoking bans, or smoke-free laws, are public policies, including criminal laws and occupational safety and health regulations, that prohibit tobacco smoking in certain areas, usually in enclosed workplaces and other public spaces. Such policies are usually enacted to protect people from the negative health effects of passive smoking or second-hand smoke (SHS) exposure
Well, which one is "external?" Headaches and stomachaches are known to exist internally, isolation is setting yourself apart which may or may not be noticed, withdrawal is declining yourself from something, while an outburst of anger is very clearly seen and heard by all. All in all, I would say D.
