Helen Found That the Expense Reports Were Not Properly Approved

Helen found that the expense reports were not properly approved while the senior accounts payable clerk was on vacation in July.Helen decided to perform a test of control on the authorization of expense reports for all the months except for July,which she will test substantively.Helen is allowed to do this because

A) the authorized expense reports for July are not material.
B) it would not be cost beneficial to test the entire population substantively.
C) the authorizations for the month of July are not representative of the population as a whole.
D) compensating controls exist in the payroll reconciliation process.