Which of the following groups of 3 are disadvantages of a "Centralize" sourcing structure? A. Operational vs. strategic focus; lacks clout; lack of standardization. B. Business unit preferences not congruent with corporate preferences; small differences get magnified; cost of supply relatively high. C. More difficult to communicate among business units; sub optimization; limited expertise for requirements. D. Tendency to minimize legitimate differences in requirements; distance from users; lack of business unit focus