Straight copy/paste from my game.
*choice Verbosity Difficulty System
#High
#Normal
#Imperial
*gosub easy_mode_defaults
*set imperial true
*finish
#Metric
*gosub easy_mode_defaults
*set metric true
*finish
#Hard Mode
#Imperial
*set hardmode true
*set imperial true
*finish
#Metric
*set hardmode true
*set metric true
*finish
#Low
#Normal
#Imperial
*gosub easy_mode_defaults
*set verbose false
*set imperial true
*finish
#Metric
*gosub easy_mode_defaults
*set verbose false
*set metric true
*finish
#Hard Mode
#Imperial
*set hardmode true
*set verbose false
*set imperial true
*finish
#Metric
*set hardmode true
*set verbose false
*set metric true
*finish