If the mean and the variance of a binomial distribution are 6 and 4 respectively, then the probability of no success is :

$\left(\frac{2}{3}\right)^{18}$ $\left(\frac{1}{2}\right)^{18}$ $\left(\frac{1}{3}\right)^{18}$ $\left(\frac{2}{5}\right)^{18}$

$\left(\frac{2}{3}\right)^{18}$