(c) 10/21
There are nine persons (three men, two women and four children) out of which four persons can be selected in 9C4 = 126 ways.
∴ Total number of elementary events = 126
Exactly two children means selecting two children and two other people from three men and two women.
This can be done in 4C2 × 5C2 ways.
∴ Favourable number of elementary events = 4C2 × 5C2 = 60
So, required probability =