The denominators could be:
⇨ 1, 2, 3, 4, 6, and 12
Work/explanation:
What are whole numbers?
Whole numbers are all positive numbers and zero.
Obviously, 0 can't be our denominator, because we can't divide by 0.
But, we can use a few choices that once simplified, they could result in a whole number.
They are 1, 2, 3, 4, 5, 6. All the factors of 12.
Hence, the denominator could be 1, 2, 3, 4, 5, 6.