D is the most likely answer because as the glacier moves across the landscape, it leaves many deep ridges into the earth. They eventually collect water and form deltas.
The right answer is D. renal regulation.
Among the many factors that modulate tension (vessels, heart strength, blood volume ...), the kidney plays a vital role because it makes an enzyme called renin that helps increase blood pressure and it regulates the outflow of sodium and water, which contribute to the elevation or diminution of blood pressure in the arteries.
The savanna is very dry and desert like. Grasslands get precipitation and have tons of grass, hence the name grasslands.
The human body is made up of 11 systems of organs.
The systems are: Circulatory, respiratory, digestive, excretory, nervous, endocrine, immune, integumentary, skeletal, muscle, and reproductive.