Which of the following statements on the components of bid-ask spread is/are correct?

	A.	If the transaction cost component is the only component of the spread, we should observe the transaction prices bouncing between the quoted bid and ask.
	B.	Price changes due to the adverse selection component have a permanent effect on prices as dealers infer values from the order flow.
	C.	If the dealer only charges for transaction cost, we should observe positive serial correlation in price changes.
	D.	Both A and B.
	E.	All of the above.