Find the Exact Value of the Function $- \frac { 2 \sqrt { 3 } } { 3 }$

Multiple Choice

Find the exact value of the function. Rationalize the denominator if necessary.
-sec 150°

A) $- \frac { 2 \sqrt { 3 } } { 3 }$
B) $- \sqrt { 2 }$
C) $\frac { 2 \sqrt { 3 } } { 3 }$
D) $\sqrt { 2 }$