Task: Question Answering
Input (English): Problem: if 2 tic equals 3 tacs and 2 tacs equal 7 tocs , what is the ratio of one tic to one toc ? 
Options: a ) 15 / 2 , b ) 6 / 5 , c ) 21 / 4 , d ) 3 / 10 , e ) 1 / 15
Output (English): c