Use a Calculator to Find the Approximate Value $\cos ^ { - 1 } ( 0.68 )$

Use a calculator to find the approximate value. Express your answer in degrees rounded to two decimal places.
- $\cos ^ { - 1 } ( 0.68 )$

A) $47.16 ^ { \circ }$
B) $34.22 ^ { \circ }$
C) $42.84 ^ { \circ }$
D) $85.69 ^ { \circ }$