7135/1 Economics Jun 2019 Quiz | AQA AS Level MCQ

The diagrams below show four possible long run average cost curves (LRAC) for a firm operating in a market where the annual sales are 400 000 units per year.
All other things being equal, which one of the cost curves, A, B, C or D, is mostlikely to enable the firm to achieve monopoly power in the market for its product?