Task: Question Answering
Input (English): Problem: a couple decides to have 6 children . if they succeed in having 6 children and each child is equally likely to be a boy or a girl , what is the probability that they will have exactly 3 girls and 3 boys ? 
Options: a ) 1 , b ) 9 / 64 , c ) 1 / 8 , d ) 3 / 16 , e ) 9 / 32
Output (English): b