Bovine veterinarians i believe
Answer:
Myogenic mechanisms
Hormones
Sympathetic nervous system
Explanation:
Myogenic mechanisms work in the arterioles that serve the glomerulus.
They cause the smooth muscle cells in the arterioles to contract and relax in response to blood pressure changes.
The sympathetic nervous system increases blood flow through the kidneys during resting conditions.
At times of stress, it decreases blood flow through the kidneys, making it more available to the rest of the body.
The hormones angiotensin and aldosterone regulate blood volume by controlling retention of Na⁺ and water.
C is wrong. The parasympathetic nervous system mainly controls visceral organs such as glands.
This is just an educated guess. As the purple pigment, caused by anthocyanins, are on the bottom side of the plant, their purpose could probably be to direct the light.
Specifically, a purple pigment on the bottom of the plant would absorb certain wavelengths near the purple spectrum, and reflect other wavelengths back toward the portion of the plant with chlorophyll. In this way, light does not simply pass through the leaf, instead it is reflected back in towards the chlorophyll to maximize the amount of light being used for photosynthesis.