Which of the following statements is correct concerning internal control in an electronic data interchange (EDI)

system?

a. Preventive controls generally are more important than detective controls in EDI systems.

b. Control objectives for EDI systems generally are different from the objectives for other information systems.

c. Internal controls in EDI systems rarely permit control risk to be assessed at below the maximum.

d. Internal controls related to the segregation of duties generally are the most important controls in EDI systems.