Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Ex Input:
Problem: 3 ltr of water is added with 9 ltr of a solution containing 57 % of alcohol in the water. the % of alcohol in the new mixture is ?
Options: a. 41.5 %, b. 42.75 %, c. 43 %, d. 45 %, e. 45.75 %

Ex Output:
b


Ex Input:
Problem: an assembly line produces 15 cogs per hour until an initial order of 60 cogs is completed. the speed of the assembly line is then immediately increased so that it can produce 60 cogs per hour until another 60 cogs are produced. what is the overall average output, in cogs per hour, for the assembly line during this whole time ?
Options: a. 20, b. 22, c. 24, d. 26, e. 28

Ex Output:
c


Ex Input:
Problem: a jar was full with honey. a person used to draw out 20 % of the honey from the jar and replaced it with sugar solution. he has repeated the same process 4 times and thus there was only 512 gm of honey left in the jar, the rest part of the jar was filled with the sugar solution. the initial amount of honey in the jar was filled with the sugar solution. the initial amount of honey in the jar was :
Options: a. 1.25 kg, b. 1.29 kg, c. 1.85 kg, d. 3.25 kg, e. 1.23 kg

Ex Output:

a