The inventory record for a business over a three-month span is shown. Inwards: January $200$ units at $10$ per unit, January $400$ units at $12$ per unit. Outwards: February $100$ units, March $400$ units. The business applies the AVCO method of inventory valuation. Calculate the value of inventory at the end of March.
- A$1\,000$
- B$1\,100$
- C$1\,133$
- D$1\,200$