At the end of the current year, $41,980 of fees have been earned but have not been

Question:

At the end of the current year, $41,980 of fees have been earned but have not been billed to clients.
a. What is the adjustment to record the accrued fees? Indicate each account affected, whether the account is increased or decreased, and the amount of the increase or decrease.
b. If the cash basis rather than the accrual basis had been used, would an adjustment have been necessary? Explain.