What is one drawback of traditional private cloud solutions as compared to public cloud?

What is one drawback of traditional private cloud solutions as compared to public cloud?
A . Traditional private cloud solutions have a CAPEX model, rather than pay-as-you-go like public cloud.
B . Traditional private cloud solutions lead to more unexpected costs than public cloud.
C . Traditional private cloud solutions make it harder for the company to audit regulatory compliance than with public cloud.
D . Traditional private cloud solutions almost always have a higher TCO than public cloud.

Answer: B