Which One of the Following Is Not a Significant Difference

Which one of the following is not a significant difference between the APT and the CAPM model?

A) APT is a much less restrictive asset pricing model
B) CAPM is an equilibrium model while the APT is not
C) The APT has weaker assumptions about investor preferences
D) APT assumes returns are generated by a factor model while the CAPM makes no reference to the underlying return generating process