If $\mathrm { x }$ Is a Binomial Random Variable, Calculate $\sigma$

Multiple Choice

If $\mathrm { x }$ is a binomial random variable, calculate $\sigma$ for $\mathrm { n } = 60$ and $\mathrm { p } = 0.7$ . Round to three decimal places when necessary.

A) $6.481$
B) $3.55$
C) 42
D) $12.6$