Final answer:
The Vertex Shader is used for each vertex of an object, and if we want to draw a triangle, it would be called three times.
Step-by-step explanation:
The correct answer is B) Vertex, three. In computer graphics, the Vertex Shader is used to process each vertex of an object. It performs calculations on the vertex position, color, texture coordinates, and other attributes. To draw a triangle, you would specify three vertices, and therefore the Vertex Shader would be called three times - once for each vertex.