Which of the following is not required for an instrument to be considered negotiable?

A) The instrument must contain an unconditional promise to pay.
B) The instrument must promise to pay a fixed amount of currency.
C) The instrument must be payable at any indefinite future time.
D) The instrument must promise to pay.
E) The instrument must be signed by the maker or drawer.

For an instrument to be considered negotiable, it must not be payable at any indefinite future time. Instead, it should specify a definite time for payment or be payable on demand. Option C, which states the instrument must be payable at any indefinite future time, is incorrect because negotiable instruments require a certain degree of predictability regarding their payment.