Choose the group which is different from the other
- 17,37 47,97
- 31,41, 53, 67
- 71,73,79,83
- 83,89,91,97
Group 1: 17, 37, 47, 97
Group 2: 31, 41, 53, 67
Group 3: 71, 73, 79, 83
Group 4: 83, 89, 91, 97
we can see that all the numbers in each group are prime except for Group 4, which contains the number 91.
Therefore, the correct answer is Group 4: 83, 89, 91, 97, as it is the group that is different from the others.