The Price of Dishwashers Has Remained Relatively Constant While the Quality

The price of dishwashers has remained relatively constant while the quality of dishwashers has improved. The CPI

A) is increased monthly to reflect the increased quality of dishwashers.
B) should not take account of any quality changes because it is a price index not a quality index.
C) has an upward bias if it is not adjusted to take account of the higher quality.
D) has an upward bias because it does not reflect the increased production of dishwashers.
E) is adjusted monthly to reflect the improvement in quality.