Sally and Warren, two audit managers assigned to the audit of Blade Enterprises, a regional distributor of knives and other cutlery products throughout the southwestern United States are discussing various ways to document their tests of internal controls with Kendra, a recent college graduate and addition to the firm. Kendra has heard about working papers being used by the auditors for this purpose, and asks Sally and Warren for examples of what might be found in such working papers. Which of the following represent examples of what might be found in these working papers? $($Select all that apply.$)$

a$.$ Details of written notifications sent to those charged with governance, documenting the state of the client's system of internal controls and what recommendations the auditors have made to fix any issues.

b$.$ Details of substantive procedures, including tests of details, performed on the client's system of internal control.

c$.$ Whether the auditors performing the tests of controls believe that the results obtained support the purpose of testing

d$.$ The particular controls that were selected for testing, and the results of the tests themselves.