A - only having one sex partner at a time.
No other answer comes close to being correct. Most modern-day societies are practicing monogamy as the main type of relationship between two people.
Hi!
There are C. 100 US Senators.
Answer: <u><em>Kant's Categorical Imperative</em></u>
Explanation: For Emmanuel Kant the <em>Categorical Imperative</em> is a philosophical center of his fundamental principle of the moral concept and duties. It can also apply our human reason to determine the right, the rational.
Kant had this kind of vision in his philosophy, that could determined what are the morals and duties of society.