Subject to the terms and conditions and within the limitations of the Plan, the Board may modify an Option, or, once an Option is exercisable, accelerate the rate at which it may be exercised, and may extend or renew outstanding Options granted under the Plan or accept the surrender of outstanding Options (to the extent not theretofore exercised) and authorize the granting of new Options in substitution for such Options, provided such action is permissible under Section 422 of the Code and the Nevada Securities Rules. Notwithstanding the provisions of this Section 5(k), however, no modification of an Option shall, without the consent of the Optionee, alter to the Optionee’s detriment or impair any rights or obligations under any Option theretofore granted under the Plan.