Which of the following accurately describes critical audit matters $($CAMs$)?$

a$.$ Matters that are material to the financial statements that do not relate to accounts or disclosures are CAMs.

b$.$ When CAMs require disclosure, PCAOB guidance states that the only disclosure needed is to identify the CAMs.

c$.$ CAMs relate to accounts or disclosures that are material to the financial statements.

d$.$ The audit report must include at least one CAM.