Which of the Following Is NOT a Property of a Cubic

Multiple Choice

Which of the following is NOT a property of a cubic spline?

A) It is flexible concerning the number of knot points to be used.
B) It uses third-order polynomials in time $t$ .
C) There are three parameters in each function between pairs of knot points.
D) It is capable of accommodating a wide variety of shapes for the yield curve.