Why does the acceleration of the train contain a direction?

Yes, that's right, a change in the direction of motion results in an acceleration even if the moving object neither sped up nor slowed down. That's because acceleration depends on the change in velocity and velocity is a vector quantity — one with both magnitude and direction.

c because the news are a source of information of things that happen on the daily and shows evidence about that particular topic

a is the best answer your welcome