Non Est Factum Is a Defence Used by Persons Who

Non est factum is a defence used by persons who want to void a contract.In plain English,the term means:

A) 'this is not a factor' - the mistake should not be considered in this legal action.
B) 'this is not my deed' - the document I signed was fundamentally different from the one I thought I was signing.
C) 'this is not a fact' - I am not responsible for this mistake.
D) 'not in my right mind' - my judgment was affected by a foreign substance which prevented a true meeting of the minds.