单选题 Which of the following statements regarding the term structure of interest rates is least accurate? A. Under the market segmentation theory, a flat yield curve is likely to become positively sloped if the demand for long-term bonds exceeds supply and if the supply of short-term bonds exceeds demand. B. Forward interest rates are the best estimates of future short-term interest rates under the pure expectations theory. C. The observed yield curve likely contains elements of liquidity preference, market segmentation, and expectations theories.