Task: Question Answering
Input (English): Problem: a fair coin is tossed 13 times . what is the probability of getting more heads than tails in 13 tosses ? 
Options: a ) 1 / 2 , b ) 63 / 128 , c ) 4 / 7 , d ) 61 / 256 , e ) 63 / 64
Output (English): a