Which of the Following Is the Reason Polynomial RD Models

Multiple Choice

Which of the following is the reason polynomial RD models can be dangerous to use?

A) There is no danger in using a polynomial model instead of a varying slopes model.
B) Polynomial models are sensitive and can produce bumps at the cutoff that are larger than they should be.
C) Polynomial models lead to further endogeneity when the error term is not continuous.
D) Polynomial models can produce multicollinearity.