Reference - Yard Mowing

Reference - Yard Mowing. Paula agreed to mow John's yard once a week for $50 per week throughout the summer. Paula, however, was having trouble getting her money from John. On one occasion, he in handwriting gave her an IOU stating "I, John Jones, owe Paula Smith $50" which he signed at the end. A couple of weeks later, John did not have the money with which to pay Paula for additional mowing, and he handwrote the following on a piece of paper and gave it to her: "I, John Jones, promise to pay Paula Smith or to bearer, the sum of $100 on Monday, July 22, 2012." Paula quit mowing John's yard, and disgusted with John, Paula assigned both documents to Vince. When Vince presented the documents to John, John refused to pay on the basis that after inspecting the yard, he decided that Paula was doing a poor job. Vince told him the documents constituted negotiable instruments, but John disagreed. Which of the following is true regarding the effect on negotiability of John's determination that Paula did a poor job mowing the yard?

A) Paula's performance prevents the instruments from being negotiable only if John meets the burden of proof of establishing to the judge by a preponderance of the evidence that Paula did a poor job mowing the yard.
B) Paula's performance prevents the instruments from being negotiable only if Paula meets the burden of proof of establishing to the judge by a preponderance of the evidence that she did an acceptable job mowing the yard.
C) Paula's performance prevents the instruments from being negotiable only if John meets the burden of proof of establishing to the judge by a preponderance of the evidence that Paula did a poor job mowing the yard, and if Paula signed a document agreeing that the instrument would lack negotiability unless she properly performed.
D) Paula's performance prevents the instruments from being negotiable only if Paula meets the burden of proof of establishing to the judge by a preponderance of the evidence that she did an acceptable job mowing the yard and that she did not sign any document agreeing that the instrument would lack negotiability upon John's objection.
E) Manner of performance is not one of the listed elements for a finding of negotiability.