; (B) the Young Men’s Christian Association, Young Women’s Christian Association, Girl Scouts, Boy Scouts, Camp Fire Girls, and voluntary youth service organizations which are so exempt, the membership of which has traditionally been limited to persons of one sex and principally to persons of less than nineteen years of age; or (C) a single-sex private social club (including an independent organization located off-campus) that consists primarily of students or alumni of an institution of higher education. .