The correct answer is A. independence of residuals.
Residuals are the differences between the observed values and the fitted values of a model. In a well-specified model, the residuals should be independent of each other. This means that the value of one residual should not be related to the value of any other residual.
If the residuals are not independent, then the model is not well-specified and the results of the analysis may be unreliable. There are a number of ways to check for independence of residuals, including the Durbin-Watson test and the Breusch-Pagan test.
B. dependence of residuals is the incorrect answer because it states that the residuals are dependent on each other. This is the opposite of what is required for a well-specified model.
C. independence of correlation is the incorrect answer because it states that the residuals are independent of the correlation coefficient. This is not an assumption of specification analysis.
D. dependence of residuals is the incorrect answer because it states that the residuals are dependent on each other. This is the opposite of what is required for a well-specified model.