Natural Selection occurs when which of the following conditions are met?

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.

thinking it would be physical characteristics

allowed for the prediction of the properties of missing elements.

it's not c. i took the quiz and got it wrong. so my best guess is b.

have a great day, and hope this .