Task: Question Answering
Input (English): Problem: if 2 ^ 2 n + 2 ^ 2 n + 2 ^ 2 n + 2 ^ 2 n = 4 ^ 22 , then n = 
Options: a ) 3 , b ) 6 , c ) 12 , d ) 23 , e ) 21
Output (English): e