Muhammad Mussadegh purchased a store in Abadan from Reza Khan for 100,000 pounds sterling. To pay for the store, Mussadegh signed a promissory note that contained the following two clauses: (a) "On or before January 1, 1992, I promise to pay Reza Khan or bearer 100,000 pounds sterling in cash or deliver title to my house in Tehran, at the holder's option" and (b) "The maker of this promissory note hereby reserves the right to extend the time of payment for six months; and the holder reserves the right to extend the time of payment indefinitely." What are the effects of these clauses on the negotiability of the note?