Understanding Motion Diagrams: Negative vs. Positive Acceleration

[Nitrate]

Homework Statement

The problem is in the attached image

Homework Equations

The Attempt at a Solution

I understand that the diagram of A is displaying negative acceleration and the diagram of B is displaying positive acceleration. However, I am struggling to find an answer for the question. I'm also wondering if the diagram of B can be flipped around and still represent the same thing. I am admittedly not the best physics student and any help is appreciated. Thank you.

 

[Nitrate]

attached image (as i forgot to post it in the previous post)

 

[haruspex]

diagram of B is displaying positive acceleration.

Acceleration is a vector, it has direction. negative acceleration is not the same as slowing down.