A US investor has $9,900 to invest for one year, either in the US, or in a Australian pension fund located in Perth, that pays 4.1% interest. Currently, $1 US buys 1.75 Australian dollars, and the investor believes the future rate will be E_t+1 = 1.69. The investor claims to be exactly indifferent between the two options, implying that the US interest rate must be

A. 5.9%

B. 7.8%

C. 8.9%

D. 10.4%