The core elements of the pattern are circle, triangle, and square.
Let us consider the first option.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383371/original_123.PNG)
In this pattern, first three elements are circle, triangle, and square. These elements are continuing for the next round also.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383372/original_123.PNG)
So, the missing element is circle.
Let us consider the second option.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383377/original_123.PNG)
In this pattern, first three elements are triangle, square, and circle. These elements are continuing for the next round also.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383381/original_123.PNG)
So, the missing element is square.
Let us consider the third option.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383394/original_123.PNG)
In this pattern first three elements are square, circle, and triangle. These elements are continuing for the next round also.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1383397/original_123.PNG)
So, the missing element is triangle.