Why is the distinction that the author makes in the sentence below important? this is an i-ready question. does anyone know?

Letter D

Explanation:

because I showed you that the trip can be easy for the Americans, so you are referring to the fact that you are trying to convince the people who are going to travel in some way that it will not be difficult for them not to think about it so much and they are born to relate the trip

its   c   : ) 0_  

answer; /// the correct answer to the above statement is (a) because of the decline on native american labor forces;