PLS PLS PLS PLS PLS HELP! 10 POINTS! TELL ME IF ANSWER IS CORRECT! WILL GIVE BRAINLEST TO FIRST PERSON'S ANSWER IS CORRECT!

The last one.

Explanation:

I think its the last one right under your first answer.

The last one

EXPLANATION:

There is salt water and freshwater, so it could not have combined, or else there would be only one type of water,  hope this helps.

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.