Following Are the Balances for Grocke Ltd at 12 December

Following are the balances for Grocke Ltd at 12 December.
Accounts receivable $39 420
Allowance for doubtful debts 1301 $38 119
If an account for $600 is written off on 15 April, what is the estimated realisable value of accounts receivable after the write-off? (Ignore any GST adjustment for the purposes of this question.)

A) $38 820
B) $38 119
C) $40 020
D) $37 519