Task: Question Answering
Input (English): Problem: frank the fencemaker needs to fence in a rectangular yard . he fences in the entire yard , except for one full side of the yard , which equals 40 feet . the yard has an area of 500 square feet . how many feet offence does frank use ? 
Options: a ) 14 , b ) 47 , c ) 70 , d ) 180 , e ) 240
Output (English): c