The most effective programmed control for preventing a check-writing software program to prepare check for a vendor not yet included in the authorized vendor file is a(an)

a.	matching of a vendor name with a name in the authorized vendor file before a check is prepared.
b.	error listing automatically generated by the computer after the checks are prepared.
c.	batch control total verification after the checks have been prepared.
d.	completeness test on fields in which data are entered,