Determine the Confidence Level for the Given Confidence Interval For \mu

Multiple Choice

Determine the confidence level for the given confidence interval for $\mu$ .
$$\bar { x } \pm 1.00 \left( \frac { \sigma } { \sqrt { n } } \right)$$

A) $84.13 \%$
B) $31.74 \%$
C) $15.87 \%$
D) $68.26 \%$