Which of the following is true regarding studies on the value of project management and project management maturity?

A. The PMI-sponsored study by Ibbs found that companies with a high maturity level spend less money on project management than companies with a low maturity.

B. The PMI-sponsored study by Thomas and Mullaly found that companies focus even more on measuring the ROI or tangible benefits of project management.

C. The PMI-sponsored study by Crawford and Cook-Davies found that several industries have reached an optimal level of organizational project management maturity.

D. The PriceWaterhouseCoopers study found that the higher the maturity level, the more difficulties the organization will have in implementing software.