25.Excluding purchases by businesses， the average

　　amount spent on a factory-new car has risen 30 per-

　　cent in the last five years. In the average household

　　budget， the proportion spent on car purchases has

　　remained unchanged in that period. Therefore the

　　average household budget must have increased by

　　30 percent over the last five years.

　　Which of the following is an assumption on which

　　the argument relies？

　　（A）The average number of factory-new cars pur-

　　chased per household has remained unchanged

　　over the last five years.

　　（B）The average amount spent per car by businesses

　　buying factory-new cars has risen 30 percent in

　　the last five years.

　　（C）The proportion of the average household budget

　　spent on all car-related expenses has remained

　　unchanged over the last five years.

　　（D）The proportion of the average household budget

　　spent on food and housing has remained

　　unchanged over the last five years.

　　（E）The total amount spent nationwide on factory-

　　new cars has increased by 30 percent over the

　　last five years.