Answer: Option (d) is the correct answer.
Step-by-step explanation:
Since it is known that ice blocks used to cool food items are prepared or manufactured by shopkeepers. So, the water used to prepare ice might not be pure and therefore, we can say that the water used in these blocks is contaminated.
Hence, when we place out food on these ice bags then the food might also become unhygenic in nature.
Thus, we can conclude that ice storage became a major drawback to using ice blocks for cooling food.