Answer:
B. The number of vertices equal the number of isosceles triangles.
Explanation:
1st figure:
No. of vertices: 4
No. of isosceles triangles: 4
2nd figure:
No. of vertices: 5
No. of isosceles triangles: 5
3rd figure:
No. of vertices: 6
No. of isosceles triangles: 6
Thus, the number of vertices equal to the number of isosceles triangles.