Please answer the question based on the following passage. You need to choose one letter from the given options, A, B, C, or D, as the final answer, and provide an explanation for your choice. Your output format should be ###Answer: [your answer] ###Explanation: [your explanation]. ###Passage:Over the past five years, the average price of new commercial housing has increased by 25% per square meter.In the average family budget for the same period, the proportion of the cost of buying commercial housing remained unchanged.Therefore, the average family budget must have increased by 25% in the past five years. ###Question:Which of the following statements about the situation over the past five years is the assumption upon which the above discussion relies? ###Options: (A)On average, the area of ​​new commercial housing purchased by each household remains unchanged. (B)The proportion of food and children ’s education in each family ’s budget remains unchanged. (C)The total cost of buying new commercial housing nationwide has increased by 25%. (D)The proportion of all housing-related expenditures in each family budget remains unchanged. I want the entire output in JSON format.
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