Answer:
c. Triangle
Step-by-step explanation:
The first image is a hexagon, with 6 sides
The second image is a pentagon, with 5 sides
The third image is a square/rectangle, with 4 sides
Logically, each image loses one side. (6 - 1 = 5, 5 - 1 = 4). The next shape will have 3 sides (4 - 1 = 3), which is a triangle
