What Value of X Will Cause the Two Vectors $\langle 5 x , - 1,2 \rangle$

Multiple Choice

What value of x will cause the two vectors $\langle 5 x , - 1,2 \rangle$ and $\langle 3,2 x , - 2\rangle$ to be orthogonal?

A) $- \frac { 17 } { 4 }$
B) $- \frac { 4 } { 17 }$
C) $\frac { 13 } { 4 }$
D) $- \frac { 13 } { 4 }$
E) $\frac { 17 } { 4 }$
F) $\frac { 4 } { 17 }$
G) $- \frac { 4 } { 13 }$
H) $\frac { 4 } { 13 }$