Answer:all the things that you keep the same in the experiment
Explanation:
Liqiud water will change from a liquid to a solid at 0°C when heat energy has been removed.
Think about it liquid water expands when it turns into ice.
Human chorionic gonadotropin (hCG) is secrete by the embryo early in pregnancy to keep the corpus luteum for dying. This positive feedback will maintain the corpus luteum, which secretes Progesterone and Estrogens throughout pregnancy, in order to keep the endometrium well to nourish the embryo/fetus.
I think it’s B
Hope that’s right
