Answer:
a vestigial structure
Explanation:
Vestigial structures are a rudimentary (or even functionless) version of a body part, but they have important functions in a closely correlated or evolutionarily close species, an example of which is the presence of eyes in fish of the genus Astyanax. The existence of these vestigial structures is strong evidence that evolution occurs in organisms, since this structure, today without much apparent function, may in the past have been extremely important to the ancestors of that species.
Answer:
d.It instructs the kidney to take in more or less water.
Explanation:
ADH(anti-diuretic-hormone) increases the water resorbtion in kidneys so it increases the blood volume
My guess would be A. I’m not sure tho. Might want a second opinion
