Answer:
Answer is option D
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An expansion in venous tone will increment heart yield and increment mean blood vessel weight. All blood vessel and venous vessels under basal conditions display some level of smooth muscle compression that decides the breadth, and thus tone, of the vessel.
Answer:
Gravitational forces.
Explanation:
The same reason the earth revolves around the sun, its all thanks to gravity!
-I hope this answers your question!
