Explanation:

- Option 1: Iodine and minerals: Both iodine and minerals are considered essential micronutrients. They are needed in small amounts for various bodily functions.

- Option 2: Calcium and fats: Calcium is a micronutrient. However, fats are macronutrients, not micronutrients. So this is correct – they are not a pair of micronutrients.

- Option 3: Minerals and iron: Minerals are a broader category that includes micronutrients like iron. Both are considered micronutrients.

- Option 4: Iodine and iron: Both iodine and iron are essential micronutrients. They play crucial roles in thyroid function and oxygen transport, respectively.

Option 2 - Calcium and fats is NOT a pair of micronutrients.