I believe the answer is D. <span> use who, what, when, where, why, and how questions to generate the details you need
The usage of 5w and 1h, will mostly cover all the information needed by the readers to understanding certain topics, so you need to make sure that all of these aspects are exist in the details or you have to do deeper information gathering for it.</span>
We know that 'migrate' means to move. So since that, we need to add the -ing, and we know that we end up with the meaning "moving".
So migrating means moving from one place to another.
This is more of an opinion than fact