Task: Question Answering
Input (English): Problem: if both 2 ^ 2 and 3 ^ 4 are factors of the number a * 4 ^ 3 * 6 ^ 2 * 13 ^ 11 , then what is the smallest possible value of a ? 
Options: a ) 6 , b ) 9 , c ) 12 , d ) 15 , e ) 18
Output (English): b