Which of the Following Contracts May Be Set Aside for Mistake

Which of the following contracts may be set aside for mistake or frustration?

A) Pam sells a computer for cash to a person she mistakenly thought she had known in high school.
B) Pam says nothing about the quality and history of a painting that she sells to Dave,despite knowing that he incorrectly believes the painting was worth more than its purchase price.
C) Pam enters into a contract to sell a colt to Dave,but Dave does not know that Pam has already sold the same colt to Donna.
D) Pam rents a cottage to Dave for a summer for $5000,and Pam later learns that because of winter storms,it will unexpectedly cost her $30 000 to repair the cottage so that it meets the needs of the rental contract.
E) Two parties enter into an agreement to purchase a container of goods,but completely innocently unknown to either party is the fact that the container of goods was destroyed by fire the previous night.