A consultant collected 960 $ of consultancy fees in advance. She erroneously debited Cash for 690 $ and credited Accounts Receivable for 690 $. The correcting entry is

a) Debit Cash, 690 $ and Accounts Receivable, 270 $; Credit Unearned Revenue, 960 $.

b) Debit Cash, 960 $; Credit Service Revenue, 960 $.

c) Debit Cash, 270 $ and Accounts Receivable, 690 $; Credit Unearned Revenue, 960 $.

d) Debit Cash, 270 $; Credit Accounts Receivable, 270 $.