please help with this question

Potentially due to demographic changes (or something else), the savings rate of Japan has decreased over the past 2 decades while it has increased for the United States. Consider the market for loanable funds in both the United States and Japan, what should be true about the real interest rates in both countries? a. The real interest rate should increase in the United States but decrease in Japan. b. The real interest rate should increase in both the United States and Japan. c. The real interest rate should decrease in the United States but increase in Japan. O d. None of these e. The real interest rate should decrease in both the United States and Japan