The renal tubule would be the vessel within the nephron loops that functions to collect ions and water back into the blood. In addition, these vessels are the one responsible for emptying the collecting duct and reabsorbs salts present in the bloodstream and disperses it back to the blood.
It is Hypotonic because it has more water than salt.
I am most positive that the answer is (C).
If the cell membrane were completely made of a polar substance, then "Non-polar" molecule cannot pass through it, and cell won't get any information from that substances
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