4/26 can be simplified by 2. So, this is not the answer. 8/21 cannot be simplified. So, it is one of the answers. 6/19 cannot be simplified. So, it is one of the answers. 9/10 cannot be simplified. So, it is one of the answers. 10/22 can be simplified by 2. So, this is not the answer.
So, the fractions in simplest forms are 8/21, 6/19, and 9/10.