When testing the control "all the checks over $10,000 must be signed by both the cashier and the accounting manager", which of the following statements most precisely describes the testable attribute? a. All the checks over $10,000 have one signature of the cashier and one from the accounting manager on them. O b. All the checks have one signature of the cashier and one from the accounting manager on them. CAll the checks over $10,000 are prenumbered, have two signatures d.All the checks over $10,000 is signed by the cashiers, who does not perform the job of the accounting manager O c