Find the Dot Product Of $\vec { u } = \langle 4,7 \rangle$

Multiple Choice

Find the dot product of $\vec { u } = \langle 4,7 \rangle$ and $\vec { v } = \langle 1,3 \rangle$ and the cosine of the angle between them.

A) $10 , \cos ( \theta ) = \frac { 1 } { 13 }$
B) $25 , \cos ( \theta ) = \frac { 5 } { \sqrt { 26 } }$
C) $25 , \cos ( \theta ) = \frac { 1 } { 25 }$
D) $5 , \cos ( \theta ) = \frac { 5 } { \sqrt { 26 } }$