The productive cycle of a human is usually regulated by

Hormones:The body's chemicals produced in the brain. Testosterone, progesterone, and estrogen control the reproductive system. The brains creates other chemicals also like serotonin, which controls your happiness levels amoung other things

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.