Select the Statement That Best Completes the Following Sentence for All

Select the statement that best completes the following sentence for all possible scenarios: 'Considering the entire value chain is important for management accounting in today's competitive environment because ....'

A) the value chain actually extends back to suppliers and forward to customers.
B) production is only one very small part of the value chain.
C) traditional systems have focused on the engineered costs of production rather than the discretionary costs of the other aspects of the value chain.
D) the study of all aspects and linkages in the chain may provide opportunities for cost reduction that are not evident when focusing on one aspect only.