The answer is compound inequality
Hi!
Your answer is C.
The vertex is the point where two different rays meet, forming an angle.
It can also simply be the point where 2 straight lines simply meet.
Option A is NOT correct because a vertex is not angle, it is a <em>part </em>of an angle.
Option B is NOT correct because, if there's only one segment, we cannot form a vertex.
See the image below for an example: