Under the Parol Evidence Rule,parties Cannot Vary the Terms Of

Under the parol evidence rule,parties cannot vary the terms of:

A) a written contract by introducing evidence of terms allegedly agreed on prior to,or contemporaneous with the writing.
B) an oral contract by introducing evidence of a written agreement.
C) a written contract by introducing evidence of another writing produced after the original contract was drafted.
D) an oral agreement by publishing notice of a subsequent modification.