Definition: In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: how many x ways can you group 3 people from 4 sets of twins if no two people from the same set of twins can be chosen ?
Options: a ) 3 , b ) 16 , c ) 28 , d ) 32 , e ) 56
Output:
d