Answer :
Step 1:
A vertex (or node) of a graph is one of the objects that are connected together.
In geometry, a vertex (in plural form: vertices or vertexes), often denoted by letters. It is a point where two or more curves, lines, or edges meet.
Step 2:
The vertex is a point I
Hence, the name of the vertex of angle JIK is the point I
Final answer
Point I Option B