Calculate the Standard Deviation of the Given Random Variable X $\sigma = 1.4$

Multiple Choice

Calculate the standard deviation of the given random variable X. Please, round your answer to two decimal places, if necessary.
X is the number of heads that come up when a coin is tossed three times.

A) $\sigma = 1.4$
B) $\sigma = 0.87$
C) $\sigma = 0.75$
D) $\sigma = 0.25$
E) $\sigma = 0.13$