Which of the following should not be a reason given by top managers to account for difficulties they are having in evaluating whether their organization is getting value for money from its information systems function?

a. Post-audits of information systems are difficult to conduct because many small development projects are scattered throughout the organization

b. Information systems plans are unhelpful as a basis for evaluation because they rarely describe what is actually done in practice

c. Many of the important benefits provided by the information systems function are intangible

d. The long-run costs and benefits of an information systems are difficult to estimate because they can be quickly eroded through technological obsolescence or strategic moves by a competitor