Peter Nolan Runs a Small Jewellery Shop in the Outskirts

Peter Nolan runs a small jewellery shop in the outskirts of Melbourne and provides specialised advice on all purchasers. Peter employs two permanent staff and is registered for the GST. For the tax period ending 31 March 2020, Peter reported the following transactions and uses the cash basis of accounting for GST.
Receipts (inclusive of GST where appropriate)
Cash sales: $55,000
Credit sales outstanding: $7,700
Gift vouchers issued: $4,400
Expenses (inclusive of GST where appropriate)
Cash purchases: $22,000
Staff salaries: $45,000
Electricity: $990
Gas heating: $880
Telephone: $440
Assuming that all tax invoices are held where appropriate, the net amount for the tax period ending 31 March 2020 is:

A) $5,690
B) $3,190
C) $2,790
D) $3,000