Which of the following statements comparing the Ho–Lee and Kalotay–Williams– Fabozzi (KWF) equilibrium term structure models is correct?

A. The Ho–Lee model assumes constant volatility, while the KWF model does not.

B. The KWF model incorporates the possibility of negative rates, while the Ho–Lee model does not.

C. The KWF model describes the log of the dynamics of the short rate, while the Ho–Lee model does not.