Between 1990 and 2000, a Particular Consumer's Income Increased by 25

Multiple Choice

Between 1990 and 2000, a particular consumer's income increased by 25%, while the price of X and of "all other goods" both increased by 10%.It was observed that the consumer's consumption of X and of all other goods both increased by 15%.

A) The consumer did not regard X and "all other goods" as perfect complements.
B) The consumer's preferences cannot be represented by a Cobb-Douglas utility function.
C) The consumer's preferences can be represented by a Cobb-Douglas utility function.
D) The consumer's preferences cannot be represented by a quasilinear utility function.
E) More than one of the above options is true.