Shannon Smith Sold Her Five-Year-Old Toyota to Doris Night on February

Shannon Smith sold her five-year-old Toyota to Doris Night on February 3.On the contract of sale,which both signed,she put the words "as is".Doris had test-driven the car with Shannon present on February 1 and had commented on a rattle in the front end and some noises in the transmission.Shannon replied to those inquiries as follows: "I think the rattle is from a loose heater cable and I know there are no transmission problems." On February 5,Doris telephoned Shannon and advised her that the car was inoperable because the transmission had seized up and Doris wanted to know what Shannon was going to do about it.That evening in the bar Shannon told her friends the above and they had the following comments and advice:
(a)Don't pay any attention to Doris,caveat emptor applies.
(b)Since the car has been delivered the contract is discharged by performance.
(c)Since you allowed Doris to examine the car and test drive it the transmission failure is solely Doris' problem.
(d)You shouldn't have said anything about the transmission but because you did you must fix the car or take it back and refund the purchase price.Shannon does not know what to do and asks for your advice.Comment on each of the (a)to (d)above with respect to the legal basis for each comment and its accuracy.Express your opinion of the liability (if any)of Shannon.