Which of the Following Situations Appears to Involve Non Est

Which of the following situations appears to involve non est factum?

A) A beneficiary and an insurance company negotiated a life insurance policy,both unaware that the subject of the life insurance policy was in fact already dead.
B) X purchased goods on credit from Y,believing Y to be Z and unaware that Y had purchased Z's business.Y was aware of X's mistake.
C) Two parties agreed to send goods by a particular ship but there were two ships with that name and each party was thinking of a different ship.
D) X,who spoke little English,signed a document granting Y an option,believing it to be a receipt.This belief was encouraged by Y.