If the real exchange rates between the USD and CAD, AUD, and BRL respectively are 1.20, 0.90, and 1.40 respectively with the percentage of trade between the US and Canada, US and Australia, and US and Brazil are 50%, 20%, and 30% respectively (assuming these are only countries on the planet!), what is the effective real exchange rate for the USD?

Question options:

a)0.9

b)1.4

c)1.2

d)1.0