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

Example Input: Problem: find the surface area of a 10 cm x 4 cm x 3 cm brick
Options: a ) 84 , b ) 124 , c ) 164 , d ) 180 , e ) 120
Example Output: c

Example Input: Problem: 50 square stone slabs of equal size were needed to cover a floor area of 72 sq . m . find the length of each stone slab ?
Options: a ) 120 cm , b ) 767 cm , c ) 88 cm , d ) 666 cm , e ) 776 cm
Example Output: a

Example Input: Problem: a specialized type of sand consists of 40 % mineral x by volume and 60 % mineral y by volume . if mineral x weighs 1.5 grams per cubic centimeter and mineral y weighs 3 grams per cubic centimeter , how many grams does a cubic meter of specialized sand combination weigh ? ( 1 meter = 100 centimeters )
Options: a ) 2 , 400,000 , b ) 2 , 800,000 , c ) 55,000 , d ) 28,000 , e ) 280
Example Output:
a