Use This Figure to Answer the Corresponding Questions $\begin{array}{ll}a.&\text {vessel 1 }\\b.&\text {vessel 2 }\\c.&\text {vessel 3 }\\d.&\text {vessel 4 }\\e.&\text {vessel 5 }\\\end{array}$

Use this figure to answer the corresponding questions.
Which vessel contains blood with the highest concentration of oxygen?
$\begin{array}{ll}a.&\text {vessel 1 }\\b.&\text {vessel 2 }\\c.&\text {vessel 3 }\\d.&\text {vessel 4 }\\e.&\text {vessel 5 }\\\end{array}$