Match the confidence level with the confidence interval for $\mu$.

 1. $\overline {x} \pm 1.645 \left( \frac {\sigma}{\sqrt{n}}\right)$
 2. $\overline {x} \pm 2.575 \left( \frac {\sigma}{\sqrt{n}}\right)$
 3. $\overline {x} \pm 1.96 \left( \frac {\sigma}{\sqrt{n}}\right)$

A. a. $95$%
B. c. $99$%
C. b. $90$%