The correct answer is a. because Confucius believed it is the model for the other four relationships.
In Confucianism, filial piety (xiao) is considered the fundamental virtue that shapes the moral fabric of society. It emphasizes respect, obedience, and care for one’s parents and ancestors, serving as a model for other key relationships, including those between rulers and subjects, husbands and wives, older and younger siblings, and friends. This reverence for familial relationships underpins social harmony and moral conduct in Confucian thought.