When May the Defence of Non Est Factum Be Raised

When may the defence of non est factum be raised?

A) when there is no written evidence of the contract
B) when there is a radical difference between what a person signed and what the person thought he was signing
C) when a person signs a document but his attention has not been drawn to a particularly onerous term
D) when the defendant forgot to have the plaintiff sign the contract
E) when a person signs a document but fails to read it first