D is the best answer hope this helps
<span>Bosnia-Herzegovina, Croatia, and Serbia
</span>
<span>Unlike primary source, a secondary source can be : B. written or created by an educated person or trained expert
In order to be categorized as a primary soruce, the surce must be directly involved and exist when the event/occurence is happening. Secondary source could be anything as long as it related to the event</span>
The answer would be A, Vietnam was divided into two countries. Hope this helps!
