The correct answer is option 3 - Freezing of water.

To understand why freezing of water is not a chemical change, let`s first define what a chemical change is. A chemical change is a process that results in the formation of new substances with different chemical properties. It often involves the breaking and forming of chemical bonds.

Now, let`s examine each option to see if it involves a chemical change:

Option 1 - Ripening of fruits: This is a chemical change. During ripening, enzymes in the fruit break down complex molecules, such as starches, into simpler sugars. This results in changes in color, taste, and texture.

Option 2 - Curdling of milk: This is also a chemical change. When milk curdles, the proteins in the milk undergo a chemical reaction, causing them to separate from the liquid and form curds.

Option 3 - Freezing of water: This is not a chemical change. Freezing is a physical change. When water freezes, its molecules slow down and arrange themselves into a crystalline structure. The chemical composition of the water remains the same.

Option 4 - Digestion of food: This is a chemical change. In the process of digestion, food molecules are broken down by enzymes and acids in