Task: Question Answering
Input (English): Problem: a couple decides to have 4 children . if they succeed in having 4 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 1 boy ? 
Options: a ) 4 , b ) 3 , c ) 2 , d ) 1 , e ) 1 / 2
Output (English): e