Instructions: 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: Problem: recipe requires 15 mins to cook . you have 7 mins hourglass and a 11 mins hourglass with you . how will you measure 15 mins using them ?
Options: a ) 15 mins , b ) 12 mins , c ) 13 mins , d ) 17 mins , e ) 20 mins
Output:
a