The standard deviation of a uniformly distributed random variable between 0 and 1 is A. $$\frac{1}{{\sqrt {12} }}$$ B. $$\frac{1}{{\sqrt 3 }}$$ C. $$\frac{5}{{\sqrt {12} }}$$ D. $$\frac{7}{{\sqrt {12} }}$$

The correct answer is $\boxed{\frac{1}{{\sqrt 3 }}}$.

The standard deviation of a random variable is a measure of how spread out its values are. A low standard deviation indicates that the values are clustered close to the mean, while a high standard deviation indicates that the values are spread out over a large range.

The standard deviation of a uniformly distributed random variable between 0 and 1 is $\frac{1}{{\sqrt 3 }}$. This can be calculated using the following formula:

$$\sigma = \sqrt{\frac{1}{2} – \frac{1}{3}} = \frac{1}{{\sqrt 3 }}$$

The other options are incorrect because they do not represent the standard deviation of a uniformly distributed random variable between 0 and 1.