Given the task definition, example input & output, solve the new input case.
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'.
Example: Problem: walking at 5 / 6 th of its usual speed a cab is 15 mnts late . find its usual time to cover the journey ? 
Options: a ) 25 m , b ) 45 m , c ) 32 m , d ) 75 m , e ) 62 m
Output: d
New speed = 5 / 6 th of usual speed new time = 6 / 5 th of usual time 6 / 5 ut - ut = 15 m ut / 5 = 15 m ut = 75 m answer is d

New input case for you: Problem: 6 men and 8 women can complete a work in 10 days . 26 men and 48 women can finish the same work in 2 days . 15 men and 20 women can do the same work in - days . 
Options: a ) 4 days , b ) 6 days , c ) 2 days , d ) 8 days , e ) 10 days
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
a