Which of the following statement about the historical patterns of the term structure is most likely correct?

A. The spot curve is always upward-sloping.

B. The spot rate can be higher than the par rate of the same maturity.

C. Long-term interest rates are more volatile than short-term interest rates.

D. For maturity of over six months, the yield curve has an upward slope most of the time.

*** D is not the right answer