Which of the following is not a feature common to forecasting?
a) actual results usually differ from forecast values
b) forecast accuracy decreases as the time covered by the forecast increases
c) forecast of aggregate demand for group of similar items tend to be more accurate than forecast for individual items
d) forecast error can be eliminated by better forecast method
e) the common assumption in any forecast method is that causal system existed in the past will continue to exist in the future

D) Forecast error can be eliminated by better forecast method                  

Explanation:

Option A) is a feature common to forecast.

Forecasts may not be perfect. The actual results of the forecast usually differ from that of the predicted values. The presence of randomness in the forecast prevents a perfect forecast. For the forecast errors, allowances should be formed.

Option B) is a feature common to forecast.

The accuracy of the forecast decreases as time period covered by the forecast increases, that is the time horizon increases. The short term forecasts are more accurate than the longer term because they contain very few uncertainties.

Option C) is a feature common to forecast.

Forecasts for groups items is more accurate than forecasts for individual items because there is a cancellation effect in the forecasting errors among the group items.

Option D) is not a feature common to forecast.

Option E) is a feature common to forecast.

The techniques of forecasting normally assumes that the underlying causal system which existed in the past will continue to exist in the future.

Thus the answer is ---

D) Forecast error can be eliminated by better forecast method            

well considering i can't see the graph, it's probably prices