Which of the following statements accurately describes the auditor's response to identified risks of material misstatement for debt and equity?

a$.$ Debt is typically only audited using control testing because of the volume of transactions.

b$.$ Given effective controls, equity is typically tested using control tests and analytical procedures.

c$.$ Audit procedures are determined before the auditor develops an understanding of the risks of material misstatement.

d$.$ The sufficiency and appropriateness of audit procedures vary depending on the desired level of assurance for the relevant assertion.