Which of the following demonstrates a violation of the $180-$degree system?

a$)$ In a scene of dialogue in which character A and character $B$ stand still and face each other, the camera records shots of both characters solely from one side of an imaginary line between them.

b$)$ In an action scene featuring one car chasing another, two separate shots capture first car A and then car B from the same side of an imaginary line between them.

c$)$ In a scene of dialogue in which character A and character $B$ move around a room together while talking, the camera records shots of both characters solely from one side of an imaginary line, even as that line changes with their movements.

d$)$

In$.$an action scene featuring one car chasing another, two separate shots capture first car A and then car B from different sides of an imaginary line between them.