Task: Question Answering
Input (English): Problem: there are 25 balls in a jar. you take out 5 blue balls without putting them back inside, and now the probability of pulling out a blue ball is 1 / 5. how many blue balls were there in the beginning ?
Options: a. 12., b. 9., c. 8., d. 7., e. 6.
Output (English): b