The concept of materiality is an underlying principle of financial reporting. Which of the following statement(s) is true?

a. Adjusting entries need not to be made to accrue immatereial amounts of unrecorded expenses or unrecorded revenue.

b. Adjusting entries may be based upon estimated amounts if there is little or no possibility that the use of anestimate will result in material error.

c. Adjusting entries can be made based on estimates for immaterial amounts of unrecorded expense or unrecorded revenue.