The real effective exchange rate for the U.S dollar ?

A. reflects only the influences of merchandise or real trade on the dollar’s exchange value
B. reflects only transactions in the currency futures market
C. is the weighted average of the dollar exchange rate relative to the currencies of important U.S trading partners adjusted for inflation?
D. is the weighted average of the dollar exchange rate relative to the currencies of important U.S trading partners unadjusted for inflation?