C. The inner core is known to be made mostly of nickel and iron. However, since there is an outer core (which is the original one that's made out of nickel and iron), your answer might be D. But if you put it the 'core' in general, the right answer should be C.
My guesses are either Portugal or Spain, but I think the country that does provide the best harbor is Portugal
It depends on what the statement is, but I would say an observation
