A Agrees to Buy a Share in B's Invention for a Certain

Multiple Choice

A agrees to buy a share in B's invention for a certain sum on the condition that C first approves the invention.However,the written contract makes no reference to C's approval.C never gives his approval.B now sues A for the purchase price.In this situation

A) whether or not C gives his approval is not relevant to the main contract between A and B.
B) C's approval is a condition precedent that must be met before there is a contract between A and B
C) the parol evidence rule applies to exclude the condition of C's approval.
D) C's approval would be a warrantee used to overcome the parol evidence rule.
E) A cannot rely on C's approval as a condition to the contract with B,because C is not a party to the contract.