Four persons are choosen at random from a group of 3 men, 2 women and 4 children. The probability of having 2 children out of 4 is :

$\frac{1}{9}$ $\frac{1}{5}$ $\frac{10}{21}$ $\frac{1}{12}$

$\frac{10}{21}$

The correct answer is Option (3) → $\frac{10}{21}$