Respuesta :
why US students who attend schools abroad tend to be more successful is the correct answer.
Option (a);
EXPLANATION:
Broad topic refers to the topic in which there are too many ideas presented by the author. In such writings, the idea the writer is trying to portray is not clear quickly and can wander from one point to another.
The topic of ‘students studying abroad tend to be more successful’ seems to be broad. Because the author would need to present many ideas about the reason students travel abroad for studies, then the curriculum there.
Then he would need to jump to how this is beneficial for them and the career options they get after studies, their salaries, etc. Only after all these discussions, he could write why are they more successful comparatively.