An underlying principle is not the same thing as an unstated assumption. Answer choice E is incorrect, but I'll try to explain how to identify principles because you will see them on other questions.
A principle will be a general statement or rule that can be applied to more specific scenarios. You will encounter many of them in regard to morality. For example: If one believes that a course of action is morally right, then one has a duty to pursue that course of action. Example: One should not lie to one's friends, unless doing so will protect a friend from harm.
Do you see why there is no underlying principle in this question? That people consume enough salt to provide significant amounts of iron is simply a piece of information given in support of the conclusion.
Does that answer your question?
zgnewquistOctober 17, 2019
Thank you, that is helpful!
rebutJuly 1, 2020
Will a principle always be stated in conditional terms?
