Task: Question Answering
Input (English): Problem: if both 7 ^ 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 ) 120 , b ) 256 , c ) 343 , d ) 441 , e ) 512
Output (English): d