The area at c will eventually drain urine into the

According to the attached image, to complete the question. the area at C will eventually drain urine into the Ureter. 
Ureter is the tube that transmits urine from the kidney to the bladder. Normally there is one ureter for each kidney. Each ureter is a narrow tube that is about 12 inches long. It has a thick contractile walls, and its diameter varies considerably at different points along its length. 

It allows water to resist freezing and thawing cycle.

Cbecause it is the only one describing a habitat