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

Input: Consider Input: Problem: a and b together can do a piece of work in 6 days and a alone can do it in 13 days . in how many days can b alone can do it ? 
Options: a ) 12 days , b ) 15 days , c ) 78 / 7 days , d ) 21 days , e ) 22 / 7 days

Output: c


Input: Consider Input: Problem: the length of minute hand of a clock is 5.4 cm . what is the area covered by this in 10 minutes 
Options: a ) 15.27 , b ) 16.27 , c ) 17.27 , d ) 18.27 , e ) 19.27

Output: a


Input: Consider Input: Problem: if shreehari walks in the speed of 4.5 km / hr from his house , in what time will he reach his school which is 750 m long from his house ? 
Options: a ) 5 , b ) 30 , c ) 10 , d ) 12 , e ) 15


Output: c