State whether the following provisions in a note impair or preclude negotiability, the instrument in each instance being otherwise in proper form. Answer each statement with either ‘‘Negotiable'' or ‘‘Nonnegotiable'' and explain why.

a. A note signed by Henry Brown in the trade name of the Quality Store.

b. A note for $450, payable to the order of TV Products Company, ‘‘If, but only if, the color television set for which this note is given proves entirely satisfactory to me.''

c. A note executed by Adams, Burton, and Cady Company, a partnership, for $1,000, payable to the order of Davis, payable only out of the assets of the partnership.

d. A note promising to pay $500 to the order of Leigh and to deliver ten tons of coal to Leigh.

e. A note for $10,000 executed by Eaton payable to the order of the First National Bank of Emanon, in which Eaton promises to give additional collateral if the bank deems itself insecure and demands additional security.

f. A note reading, ‘‘I promise to pay to the order of Richard Roe $2,000 on January 31, 2011, but it is agreed that if the crop of Blackacre falls below ten bushels per acre for the 2010 season, this note shall be extended indefinitely.''

g. A note payable to the order of Ray Rogers fifty years from date but providing that payment shall be accelerated by the death of Silas Hughes to a point of time four months after his death.

h. A note for $4,000 calling for payments of installments of $250 each and stating, ‘‘In the event any installment hereof is not paid when due, this note shall immediately become due at the holder's option.''

i. An instrument dated September 17, 2010, in the handwriting of John Henry Brown, which reads in full: ‘‘Sixty days after date, I, John Henry Brown, promise to pay to the order of William Jones $500.''

j. A note reciting, ‘‘I promise to pay Ray Reed $100 on December 24, 2010.''