A sales transaction was coded with an invalid customer account code (XXX-XX-XXX rather than XXX-XXX-XXX). The error was not detected until the updating run when it was found that there was no such account to which the transaction could be posted. The best control procedure to prevent this kind of situation would be: Select one: O a. Hash total b. Check digit c. Validity test O d. Either B or C Which of the following is not one of the steps in REA modeling? Select one: O a. Create entity-relationship diagrams O b. Convert entity-relationship diagrams into database tables O c. Prepare financial statements in databases O d. Identify business and economic events