Brett Displays His 1880 Spinning Wheel at an Antique Trade

Brett displays his 1880 spinning wheel at an antique trade show.Mary sees the spinning wheel and is interested in buying it.Brett says he will sell it for $2,500.Mary says she really likes the spinning wheel but is only willing to pay $1,500.Which of the following is correct?

A) Mary's counteroffer terminates Brett's offer of $2,500.
B) If Brett rejects Mary's counteroffer, she can still accept the original offer of $2,500.
C) Brett's statement was not an offer bur merely an opinion.
D) Mary's counteroffer is not valid as she did not wait a reasonable time before making it.