(b) The requirement is to identify the correct statement
concerning internal control when a client uses an electronic data
interchange system for processing its sales. Answer (b) is correct
because encryption controls are designed to assure that messages
are unreadable to unauthorized persons and to thereby control
the transactions. Answer (a) is incorrect because suppliers are
not ordinarily included in a company’s sales controls and because
even in a purchasing EDI system all suppliers need not be included.
Answer (c) is incorrect because a value-added-network
that provides network services may or may not be used in an EDI
system. Answer (d) is incorrect because “paper” versions of
transactions typically disappear in an EDI system.