In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Input: Consider Input: Problem: a spirit and water solution is sold in a market . the cost per liter of the solution is directly proportional to the part ( fraction ) of spirit ( by volume ) the solution has . a solution of 1 liter of spirit and 1 liter of water costs 30 cents . how many cents does a solution of 1 liter of spirit and 2 liters of water cost ? 
Options: a ) 13 , b ) 30 , c ) 50 , d ) 51 , e ) 52

Output: b


Input: Consider Input: Problem: find the smallest number that should be multiplied with 54000 to make it a perfect cube . 
Options: ['a ) 4', 'b ) 5', 'c ) 6', 'd ) 3', 'e ) 7']

Output: a


Input: Consider Input: 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 320 square feet . how many feet offence does frank use ? 
Options: a ) 14 , b ) 47 , c ) 54 , d ) 56 , e ) 240


Output: d