Task: Question Answering
Input (English): Problem: if the perimeter of δ acd is 9 + 3 √ 3 , what is the perimeter of equilateral triangle δ abc ? 
Options: ['a ) 9', 'b ) 18 − 3 √ 3', 'c ) 18', 'd ) 18 + 3 √ 3', 'e ) 27']
Output (English): c