A 3x3 grid is presented.
The top row contains: [A square with a small black circle in the top-left corner], [A square with a small black circle in the top-right corner], [A square with a small black circle in the bottom-right corner].
The middle row contains: [A triangle with a small black circle in the top-left corner], [A triangle with a small black circle in the top-right corner], [A triangle with a small black circle in the bottom-right corner].
The bottom row contains: [A circle with a small black circle in the top-left corner], [A circle with a small black circle in the top-right corner], [A missing square].
Which of the options below completes the grid?