This dude was sitting in the chair. Someone pulls the chair out from under him. He does not move in the direction of the chair. He simply falls to the ground in the same spot he was sitting. This shows inertia because:

This shows inertia because inertia is an object's resistance to change in motion. When the person (imma call them a she) who pulled the chair from under the guy did that, the chair was the one affected by the force of the girl, not the guy. The guy continued heading in the direction he was originally going, which was down.

At least, that's about how I would answer this question.

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.