Trickiness w/ exchange rates

Does anyone have a reliable way to tell which is the DC vs the FC for the econ, PM and futures problems??

look for parts of the question where they say where the investor is from…that’s usually DC…

I don’t think you can do that - look at question 12 on page 123 of CFAI text 6 - can’t figure out for the life of me why the Euro is the FC when the company in question is based in Germany and the rate is quoted GBP per EUR - anyone???