(a) To serve or allow to remain in any area classified by the board as off-limits to any person under the age of twenty-one years;
(b) For any person under the age of twenty-one years to enter or remain in any area classified as off-limits to such a person, but persons under twenty-one years of age may pass through a restricted area in a facility holding a spirits, beer, and wine private club license;
(c) For any person under the age of twenty-one years to represent his or her age as being twenty-one or more years for the purpose of purchasing liquor or securing admission to, or remaining in any area classified by the board as off-limits to such a person.
(2) The Washington *state liquor control board shall have the power and it shall be its duty to classify licensed premises or portions of licensed premises as off-limits to persons under the age of twenty-one years of age.