Task: Question Answering
Input (English): Problem: for any number z , z * is defined as the greatest positive even integer less than or equal to y . what is the value of 6.45 – 6.45 * ? 
Options: a ) 0.45 , b ) 0.5 , c ) 6.45 , d ) 0.25 , e ) 6.0
Output (English): a