*Please explain

If a market maker posts a quote of 10.00 10.10 [25x10], which of the following actions is the market maker willing to take? A. Sell 1,000 shares at $10.00 and buy 2,500 shares at $10.10 B. Buy 2,500 shares at $10.00 and sell 1,000 shares at $10.10 C. Sell 100 shares at $10.00 and buy 250 shares at $10.10 D. Buy 250 shares at $10.00 and sell 100 shares at $10.10