Scienter Exists in Which of the Following Cases

Multiple Choice

Scienter exists in which of the following cases?

A) Martin knows that the transmission on his truck is defective,but does not tell this fact to potential buyers.
B) The racehorse that Karen is trying to sell has a genetic defect,but Karen does not know about the defect,and so she does not warn potential buyers.
C) Jake,a real estate agent,tells a client that he has a house that "will make all her dreams come true."
D) John forces Bill to sign a contract to sell John a car below market value.