A frog and an apple tree do not have many things in common except they are both living things. As such, it is evident that they both-​

Are composed of at least one cell (B)

Explanation:

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.

answer; an inhibitory postsynaptic potential;