If the mean and variance of binomial distribution are 2 and 1 respectively, then the probability of at least 1 success is:

$\frac{3}{4}$ $\frac{2}{3}$ $\frac{7}{8}$ $\frac{15}{16}$

$\frac{15}{16}$

The correct answer is Option (4) → $\frac{15}{16}$