Spartan men devoted their lives to military service, and lived communally well into adulthood. A Spartan was taught that loyalty to the state came before everything else, including one's family.
20 years difference - (0AD - 10BC = 10 years) + (0AD + 10AD = 10 years)
C. Had propaganda made that promoted them as being aligned politically and personally.
Your answer is.....The flag