Consider this limited-order book of a market marker/dealer:

Bid		Ask
Price ($)	Shares	Price ($)	Shares
49.750	500	50.250	100
49.500	800	51.500	100
49.250	500	54.750	300
49.000	200	58.250	100
48.500	600

If you place a market sell order for 2000 shares, at what average price will it be filled?

a). $49.25

b). $49.75

c). $51.55

d). $49.45