Which of the Following Statements Best Defines Exchange Rate

Which of the following statements best defines exchange rate?

A) The price paid to borrow debt capital.
B) The actual rate charged on a loan that compensates investors for postponing consumption, inflation, and risk.
C) The number of units of a given currency that can be purchased for one unit of another currency.
D) The nominal, risk-adjusted rate of return that is actually published in financial publications.
E) The rate of interest that offsets inflation and provides the required real return on a riskless investment.