There are 20 children in the cast of a class play, and 8 of the children are boys. of the boys, 4 have a speaking part in the play, and of the girls, 8 do not have a speaking part in the play. if a child from the cast of the play is chosen at random, what is the probability that the child has a speaking part?
a)2/5
b)1/2
c)3/5
d)3/4