Vein because they have valves to prevent back flow of blood.
<em>The </em><em>energy </em><em>released</em><em> by</em><em> the</em><em> </em><em>hydrolysis</em><em> </em><em>of </em><em>ATP </em><em>is </em> <em><u>7.3 kcal/mol of </u></em><em><u>energy.</u></em>
Dont Listen to me but i (Think) it's Nitrogen
B I think is the correct answer
