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 Input: Problem: a car drives 90 miles on local roads at 30 mph , and 75 miles on the highway at 60 mph , what is the average speed of the entire trip ?
Options: a ) 36 mph , b ) 40 mph , c ) 39 mph , d ) 42 mph , e ) 38 mph
Example Output: c

Example Input: Problem: if 4 spiders make 3 webs in 9 days , then how many days are needed for 1 spider to make 1 web ?
Options: a ) 9 , b ) 12 , c ) 27 , d ) 24 , e ) 16
Example Output: b

Example Input: Problem: in a race of 1000 m , a can beat by 100 m , in a race of 800 m , b can beat c by 100 m . by how many meters will a beat c in a race of 800 m ?
Options: a ) 122.9 m , b ) 170 m . , c ) 122.2 m , d ) 222.9 m , e ) 12289 m
Example Output:
b