Answer: Performance of services on account
Explanation: Under the accrual basis of accounting the revenue from an activity is recorded when it is earned, that is, when the activity is completed. On the other hand, in cash basis of accounting the entry is recorded when cash is received.
So when the services are performed on account then the debtor will arise and the revenue is recorded if he organisation is following accrual basis.
On the other hand nothing will be recorded under cash basis since the cash is not received yet for the services performed.