duration of an option as specified in the option contract, during which
the person holding the option has the privilege of deciding whether or
not he will exercise it, i.e., buy or sell, as the option might call for.
The longer the duration, all things being equal, the more valuable
the option. Under the Internal
Revenue Code 1954, "restricted stock options" may be exercised within
ten years from the date of granting of the option.